FAQs about Light and Lighting for Marine Systems 16 Related Articles: Marine Light, & Marine Aquarium Light Fixtures and Canopies, Lighting, Lighting Marine Invertebrates,  Anemone Lighting, Acclimating Symbiotic Reef Invertebrates to Captive Lighting, Coral System Lighting, Moving Light Systems, Moving Light Systems,  Related FAQs: Marine System Lighting,  FAQs 2, FAQs 3, FAQs 4, FAQs 5, FAQs 6, FAQs 7, FAQs 8, FAQs 9, FAQs 10, FAQs 11, FAQs 12, FAQs 13, FAQs 14, FAQs 15, FAQs 17, FAQs 18, FAQs 19 & FAQs on Marine Lighting: Fixture Selection 1,  Fixture Selection 2, Fixture Selection 3,  (incandescent, fluorescent, MH/HQI, LED, natural...), Lamp/Bulb Selection 1, Lamp/Bulb Selection 2, (See Fluorescent, LED, MH... below), Installing, Waste Heat Production/Elimination, UV Shielding, Measure, Troubles/Repairs, By Manufacturer Make/Model: & Actinic Lighting, Metal Halide Lighting, Fluorescent Lighting, Compact Fluorescent Lighting,  Small System Lighting, Lighting Marine Invertebrates,  LR Lighting,  Tridacnid Lighting,

VHO or VHO with halide? I am setting up a new 75 gal thru-the-wall my question is for a reef set-up with various corals and some community fish, I have a 660 icecaps VHO ballast (thinking about a 4-ft 4-lamp configuration) and I'm thinking about putting in a single lamp NO to simulate dusk and dawn. my questions are, is the dawn and dusk thing a good idea and what kind of split should I have as far as actinic and 50/50 (or what other type bulb is recommended for VHO) < Using the 50/50 and actinics is a good set up.  Four bulbs over a 75 gal tank is not much light.  It will be fine for soft corals, but not stony corals.  As for the dusk/dawn, it really won't make a difference to the tank, it will just make the tank look much cooler to you. > I do like the bluish hue and the way iridescent green corals look with the actinic. I could possibly acquire an MH ballast and socket but do I have enough hood to accommodate all these type fixtures or will the VHO suffice. < VHO is fine, but for good coral growth and color the halide will certainly help out.  I'd try a halide with two VHO's before I'd use four VHO's. > Thanks in advance Spence <  Blundell > How long to leave lights on? thanks for the advice...can you also advise how long each day the light should be on? < I'd say around 14 hours per day. > <  Blundell  > Lighting Thank you very much for corresponding with all my matters I have currently decided that I will be going with a hood that will house 2 HQI 150 watt bulbs and two 96 watt pc actinic bulbs accompanied by lunar lights. Will this be too much lighting for my 46 bow front which measures 36x16x20.<Hello Freddy.  No, that won't be too much light.  No harm will be done.> I can probably drop that wattage of the bulbs in the hood, if I had to. The hood will come with custom legs, they will allow the hood to stand on the sides of the tank from left to right and will lift the hood 6 inches above the tanks water level. I think I may have over did it with lighting I'm kind of worried I will be burning my animals when set up. Please let me know what you think.<James (Salty Dog) thank you Freddy

Using fibre optics to light a reef tank Hi <Hello there> Firstly, thanks for the great website. I'm quite interested in using fibre optics to light my tank and I was wondering if you think is would be something worth trying? Regards, Tony Davey <Ah, yes. Some folks are working out the bugs (intensity, quality of light, cost issues) as we key and read... for pet-fish applications. Definitely worth trying. Bob Fenner> Please forgive me... Another lighting question  <Hello Jim, good name> Dear Bob or Anthony, I am going to ask a question that has been asked so many times. I really try to research as much as possible and try not to waste your valuable time with redundant questions. I have upgraded my lighting on your advice to a Current USA (4) bulb 96 watts. My question being it comes with (2) daylight and (2) Actinic. Is there a better combination I should be going with that would keep my soft corals happier. Once again I apologize for the question but I figure if I am going to spend all this money on a upgrade I would like to get the most out the light. (Boy I wish someone would spend this much time and money trying to make me happy) I was reading so many different opinions on your site. It seems like Anthony and yourself seem to favor Daylight bulbs and many others say to keep the Actinic. Just a little confused.<Using daylight and actinic should be no problem.  Personally I prefer 10K and actinics.  James (Salty Dog).>Thanks again!! Lighting For A Deep Tank Hello <Hey there! Scott F. at your service> I have a 44 gallon pentagon corner tank.  I'm just getting started with a saltwater tank...have some live rock and damsels only at this point while the tank cycles.  Eventually, I would like to add some soft corals and the like.  Since most lighting fixtures with high wattage don't fit on the top of my awkward tank, I was advised at a local store to get a hanging metal halide light...250 watts for my 44 gallons.  I was reading some of the FAQs on your site and your advice seems to indicate that 250 watts is too much (also, they advised me that the light should hang 6" from the water).  Please advise on the proper lighting system for my needs...36" deep tank, limited space on the top.  Thanks! <Well, in many cases, it can be argued that 250 watts for this sized tank is overkill. However, I have many hardcore SPS coral-keeping friends who would argue that this is a minimum light required for your tank! In fact, many soft corals will thrive under intense light, too. In a tank of this depth, their argument may be quite logical. Usually, "conventional wisdom" (is there such a thing these days?) dictates that you'd use 150-175 watt halides for tanks up to 30" in depth. In your case, I'd go for the 250 watt light, with a few caveats. The first is that you need to consider the heat generated by this wattage of lighting in your tank. The second is that you need to carefully acclimate all organisms to this intense lighting. In the long run, the 250 watt lighting will give you greater flexibility when the urge to keep SPS corals strikes (it may not be interesting to you right now-but if you hang out with enough fellow reef nerds, it's inevitable, LOL). Hope this is of use to you! Good luck! Regards, Scott F.> Lighting Hi Bob and Crew, I have a quick lighting question. I have a 90 gallon tank with (4) 65 watts PC. I want a little more light in the tank. Do you think I would be better off with (4) 96 watts PC or (4) 110 watt VHO? < I would go with the 4 96PC, they are a little more efficient dollar/watt.  A 90 is getting close to border line as far as depth for PC's if you ever intend on getting hard corals, I believe for softies you should be fine>  James. I have only soft coral in the tank now (will keep it that way) and all seem to be doing well. Your advice is greatly appreciated! Lights for a 46 gal bow front tank HI I AM SETTING UP A REEF I AM USING A 46 BOW TANK 36X15X20 I WANTED  TO KNOW I WAS GOING TO ORDER ORBIT COMPACT FLUORESCENT WILL THIS BE ENOUGH  LIGHTING IN COMPARISON TO METAL HALIDE LIGHTING I PLAN ON KEEPING MOSTLY SOFT  CORALS AND MAYBE A FEW CLAMS THESE ARE THE SPECS ON THE HOOD  I WOULD  APPRECIATE ALL THE HELP I CAN GET THANK YOU FOR YOUR TIME . FOTI Unique power  compact lighting system simulates 24-hour day and night light cycle, ideal for  reef aquariums with higher lighting requirements. Internal fan provides quiet  and efficient ventilation. Includes Sun Paq bulbs (Dual Actinic are 420nm/460nm  & Dual Daylight are 6,700?K/10,000?K),<< Are these pc bulbs or VHO? >> Lunar Lights, reflector, mounting  legs, acrylic lens, two separate power switches and three independent power  cords for lighting units. Square pin configuration. << Okay so they are pc bulbs.  I'm going to be they are 55 watt bulbs.  This is not enough light for clams or SPS corals.  It is enough for soft corals, but still not much light.  I had that much light on my 29 gal but it wasn't enough.  I think I'd look at some bigger light systems if you really want clams. >> <<  Blundell  >>

Re: Ultimate low power consumption saltwater aquarium -suggestion, LEDs Bob, I was reading about this man trying to light his soft coral tank with LED's. There are a few tanks which use them on the nano-reef.com forums! www.nano-reef.com/forums is the address, a simple search is all that is needed here. So far I think the tanks have been running good. Also, I believe there is a step by step in one of the threads, so.... If he needs help wiring them up, It's all there for him. Hope that helps Daniel Babcock. <LEDs are indeed going to "hit the aquarium market" soon... as you had stated, due to low operating costs (electricity, replacement of fixture). They have the intensity (have seen a million candle power unit in operation), and issues of other aspects of light quality are being worked out. Bob Fenner> How much light for a 130 gal? HI, I am so confused about having enough lighting on my aquarium, it is 130 gallon  it is 72x18x24,i am running 2 Coralife power compacts,(2) 55watt bulbs,(2) 65 watt bulbs, my corals are not doing good, nitrate 0,saltatity .023,ammonia 0, calcium at 450,everything checks out good, I have soft coral and hard corals, spaced out plenty of room, have at least 75 -100 lbs of live rock all the fish are fine, so what about the lighting do I need to change it,<< Absolutely!  That is nowhere near enough light if you ask me.  I had four 65 watt bulbs on my 30 gal reef tank, but replaced it because it wasn't enough.  I highly recommend looking at some other aquariums in your area.  For me, if I had that tank, I'd use three 250 watt halides and four 110 watt VHO actinics. >> if so what lighting would you suggest I have been looking at orbit compacts, and lunar bulbs, I really don't understand how many watts I need, that really confused me,<< They confuse us all.  I'm always upgrading my lights as I find better lights.  But for most hard corals, you are going to need several hundred watts of halide lights. >> thanks   <<  Blundell  >> Using sunlight Hello, Troy here again. << Blundell here again. >> My tank is running fine, thanks to all you guys, cheers. I have a question about sunlight.   I have a large window in the same room as my tank.  It usually gets pounded with sunlight, especially in the winter being lower in the sky than summer.  I had some direct sunlight hitting my tank.  So I put up some solid blinds (no sunlight) but it makes my living room like a dungeon. << Let the light in. >> I have since removed the blinds and coved the window in 1000H or tracing paper.  This diffuses the light a lot and maybe 75%  the sunlight hitting my tank is heavily diffused and only reads as a 0.7-1.4 stop (light meter)   do you think I will have any problems with this amount of sunlight (morning only) hitting my tank.    << Some of the best tanks I've seen recently were tanks right in front of windows to use all that light.  If it were me I'd encourage that light to come in. >> Tank you for all your help (great site) << Try checking out some of the sunlight tanks out there.  My tank I had by the window (before I moved) had the fastest coral growth I've ever seen. >> Troy :) <<  Blundell  >>

Lighting and Fish Compatibility Hi--well another question or two that hopefully is not a bother.<No, Not at all.> I am expanding my FOWLR from a 55g to a reef 90g with a 30g sump.  My present lighting system on the 55 consists of 4x65W PC half actinic and half daylight.  For many reasons, I will not be able to go to MH on the 90g tank which I hope isn't your immediate answer and also I have no intention of getting into the high light requirement corals, sticking mainly with the softs. So, the first question is can I mix PC with VHO?<Yes, Absolutely.>  My first thought is to add 220W of VHO, half actinic and half daylight.  If I can mix them, what temperatures would you suggest?<2 actinic and 2 67k.>  If I cannot mix them, what do you think of adding another 4x65w of PC to the 90 for a total of 460w?<I don't think it will be enough if you go that route.>  Is it better to just switch altogether, again assuming no MH and go to all VHO?<No, Mix them.  The more light you have the better.  Just make sure they are the same temp. agreement.> Second half of the question is in regard to Tang compatibility.  I presently have one yellow tang.  I've been told that tangs need to be in odd numbers but am not sure if that refers to a specific type of tang.  For example, is it safe to add one Blue or perhaps a Naso, don't think I have enough tank for the Naso though? As always, thanks much for your advice. Larry <Larry, Mixing tangs can be tricky.  I would mix them when you turn the tank over.  Don't put the yellow in first and then a week later try and add one.  They will fight.  Yes, the tank is too small for a Naso tang.  good luck.  MikeB.>

Lights and refugium questions for a 125 gal Paul and the rest of the gang;     Thank you so much for your response, and for all of the other helpful information on your site.  After talking to one of the guys at the LFS, I think I'm going to  go with the Coralife Aqualight Pro.  The 72" version has 3 150 watt HQIs and 4 96 watt PC's. << Sounds good. >> However, the guy at the LFS told me that because of the glass brace that runs across the top in the middle (125 gallon 72x18x23), and the overflow being in the center of the back pane of glass that much of the middle HQIs usefulness would be negated. << Very true.  Many people have that brace removed and replaced with a clear acrylic brace.  Or, just having their lights not centered directly over their tank. >>  He suggested that the 48" (2 150 watt HQIs, 2 96 watt PC's) would be sufficient for the LPS corals I intend to keep. << On a 125 gallon?  I have that much light on my 30 gallon!  That doesn't sound like anywhere near enough light. >> Any thoughts/recommendations you have on the matter would be much welcome and greatly appreciated.  Also, for the sump based refugium that they make and sell there, the protein skimmer is in the last section of the sump, so that the raw tank water first flows through a partition filled with live rock, overflows into the refugium, which then overflows into the section housing the skimmer and is finally pumped back up to the tank.  He said the reason is that it allows for a higher water level in the sump/refugium, which means greater system volume, and that makes sense to me.  However, most of what I've read says that it is best to have all raw tank water pass first through the skimmer. << Yes, I'd go skimmer first, then refugium. >>  The skimmer I am getting is an ASM G2, and my primary goal of the refugium is to generate plankton for the tanks inhabitants.  Your thoughts? << I'd either hook the skimmer up in addition to the refugium (so it doesn't affect water level and volume) or just run it at the beginning.  It doesn't do any good to have a refugium (regardless of size) if you are just pulling out your plankton into your skimmer. >>  Once again, thanks in advance. Adam G. Mesa, AZ <<  Blundell  >>

VHO Lighting Query Hello, my best wishes for this lovely season. <Cheers! Ryan with you today> My tank is a 4 feet long, *?1 feet 3 inch. deep. less than 50 US gallons (3 years old).  I have 1 yellow tang, 1 yellow tail damsel, 1 pink skunk, 1 mandarin fish and 1 fire fish. Also 1 boxing shrimp, at least 20 turban snail, 4 hermit crabs (2 blue legged and 2 red). Also my tank have some corals (leather finger = more than 1 year with me, growing, a couple of green polyp colonies growing, colonies of Ricordea and similar, 3 gorgonian branches, 2 urchins, 1 tongue (Polyphyllia) it grows 1/2"- 3/4" this year). 1 long tentacle anemone, 1 flowerpot (Anthony already quarreled me for that :( ) <I see...Save me the breath!> PH is 8.2-8.3 (day/night), ammonia, nitrite, nitrate, 0 or not detectable, 10% weekly water changes. Ok my question, my tank is illuminated by VHO light (URI lamps), IceCap Ballast.  3 lamps, 330 VHO Watts.  2 actinic white and 1 actinic 03.  Do you think that this is enough light for my inmates, corals and anemone? <I'd say that you've got just enough light for medium growth in most of these animals.  You'd notice a major difference in their growth rates if you switched to MH, but it's entirely optional.> Thank you very much. <No worries!  Enjoy your Holiday.> Carlos D?z Light Choices... Hi, <Hey there! Scott F. here today!> I'm currently considering a lighting improvement to my 105 gal reef tank, and I was wondering if you could provide some insight.  Before I get into the details, I'll explain my current setup: 105 gal tank, varying soft and LPS corals, 4 VHOs 110W each My corals are doing fairly well, but I find that I'm limited (based on lighting needs) in the placement and selection when adding new corals.  I first started seriously considering upgrading my lighting when I noticed the incredible difference in appearance with the metal halide lighting at the local fish stores.  I AM looking for some of that 'shimmer' in my tank, but not at the expense of stressing my existing corals. <Good thinking and consideration on your part.> Also, I believe the deepness of my tank demands slightly more lighting.  Just having a little more brightness would probably improve the appearance significantly. <Of course, providing proper spectrum is also important...> Just to provide one data point... I have an Open Brain that is at about mid-tank level.  It's been doing 'ok', but I notice that it's greenish coloration isn't as impressive as some I've seen under metal halide lighting. <That is quite possible.> Here are the options I'm considering (in no specific order of preference): Option 1:  Simply add two more VHOs to increase my total wattage to 660 W (6-VHOs) Option 2:  Remount my current VHO fixtures to make room for some additional metal halides.  This would be two metal halides with two VHOs on each side.  I'm guessing somewhere around two 150W or 175W MHs? <In most tanks under 24" of depth, 150 or 175 watt bulbs would work.> Option 3:  Remove two of my VHO fixtures to make room for some additional metal halides.  This would be two metal halides with one VHO on each side.  I'm guessing somewhere around two 250 W MHs? <If you take the time to acclimate your corals to the intensity, and if you are planning on moving into more demanding (in terms of light) corals down the line, then this would be the best choice, IMO.> I would greatly appreciate any thoughts or suggestions you may have. Are there any trade-offs in advantages, or does one option really stand out as the best? Thanks in advance, John <Well, John, as indicated above, the 250's are the most versatile choice if you understand the need to acclimate your corals carefully. That would be my call...But do ask yourself what your eventual goals are for this tank when planning your lighting setup. Best of luck! Regards, Scott F.> DIY or not lighting I'm looking into building/purchasing a 48" long light with hood    for my 55 gal reef tank. I HAVE DECIDED THAT I ONLY WANT SOFT CORAL AND FISH IN THE TANK. Which is better to use to achieve 260 watts of light for the tank, using   4 24" bulbs, 2 full spectrum and 2 actinic, or using 2 48" bulbs, 1 full    and 1 actinic? <I'd go with the longer, higher wattage bulbs.  Or whichever is cheaper.> Will a fan be necessary if I use compact fluorescents only at night? <Probably not, but every tank varies.  I'd put one in or at least drill a hole for it assuming that it would need it.> I've looked at Coralife, orbital and satellite light kits.  Is there a web sight that compares these? <Not that I know of, but all are high quality brands.  Check hellolights.com for good lighting deals.  premiumaquatics.com also has a good selection and great service.> Do you know of a diagram for building my own if I obtain most of the parts from home depot (hardware store)? <It's fairly simple with PCs, just wire a ballast to the bulb.  I would buy a professionally made reflector.> I was looking at metal halides, but a friend told me the bulbs can explode, they are very hot, <They can, but only if they're splashed with water when on.  Stick them 8-12" above the water to prevent this.  They're actually easier to fan cool than a long fluorescent fixture because the heat is produced at one point rather than the length of the tank.  They do get very hot though.>   for the same wattage they cost 2 to 3 times as much to run compared to compact fluorescent bulbs (remember I don't want hard corals). Is this true? <Depends on the ballast and brand of bulb.  Some MH ballasts rated 250W will actually pull 300W or so.  This is true of PC ballasts as well though.  But 2-3 times more is a bit of an exaggeration.  Keep in mind it also takes a much lower wattage MH bulb to produce the same light as PC.  For instance 2 70W MH bulbs would probably be adequate for your tank.  They also don't need replaced as often.  All in all, MH is the cheapest method in the long run.> I could only find one article on T-5 fluorescent bulbs.  It claimed that the bulbs were much more efficient and cost effective than conventional compact fluorescent bulbs.  Have you found this to be correct?  Do you think they will replace conventional compact fluorescents? <I've never used T-5s, but they are more efficient.  They have an internal reflector.  I can't say costwise though.> I look forward to hearing your expertise! <Good luck with your tank!> J. Bladykas

Lighting I'm looking into building/purchasing a 48" long light with hood for my 55 gal reef tank. I HAVE DECIDED THAT I ONLY WANT SOFT CORAL AND FISH IN THE TANK. Which is better to use to achieve 260 watts of light for the tank, using   4 24" bulbs, 2 full spectrum and 2 actinic, or using 2 48" bulbs, 1 full    and 1 actinic? <Less actinic... this radiation is really only good for looks> Will a fan be necessary if I use compact fluorescents only at night? <Likely not> I've looked at Coralife, orbital and satellite light kits.  Is there a web sight that compares these? <Not as far as I'm aware... though there are articles by Sanjay Joshi, Dana Riddle and others that present data that mention these and other brands. Not easy to search, find online though... Need to visit a large (college) library re> Do you know of a diagram for building my own if I obtain most of the parts from home depot (hardware store)? <See OzReef.org> I was looking at metal halides, but a friend told me the bulbs can explode, they are very hot,  for the same wattage they cost 2 to 3 times as much to run compared to compact fluorescent bulbs (remember I don't want hard corals). Is this true? <To an extent, yes... MH rarely actually explode, though has happened... get very hot, are glass encased... need to avoid splash, spray, and salt encrustation... and do use much more electricity> I could only find one article on T-5 fluorescent bulbs.  It claimed that the bulbs were much more efficient and cost effective than conventional compact fluorescent bulbs.  Have you found this to be correct? <Yes, they are the current best available technology in fluorescents>   Do you think they will replace conventional compact fluorescents? <I do think so... and will in turn be supplanted> I look forward to hearing your expertise! J. Bladykas <Thank you for your thoughtful questions. Bob Fenner> Question regarding lighting for a reef aquarium Hello!  I read your website on a regular basis and have found much useful information on it.  I am somewhat new to the hobby and currently have a 125g FOWLR tank.  I want to upgrade my lighting so I can maintain corals.  I would like to upgrade to allow me to maintain clams and SPS, although I plan to start out with easier species.  My quandary is this. The aquarium is standard 125g (72" long, 24"deep).  I have an oak canopy already in place.  I have done much research regarding lighting choices and want to make the right purchase since I only want to do this once.   Since I have a canopy, I would like to mount the lighting in the canopy.  I have read that MH lighting seems to be industry standard, however I have also read that T5 lighting seems to be the up and coming technology in aquarium lighting.  I found a T5 retrofit system that would fit my aquarium. it uses 8 80W T5 bulbs for around $450.00.  I could purchase a combination MH(2 175W) and VHO/T5 (2 96W VHO/2 80WT5) system for a little bit more.  Other than the shimmering appearance and better light penetration that MH has over T5, what other factors do I need to be aware of? <Heat, the potential for fire... and some growth and color advantages of MH> For instance, if I go with the MH system, would I need to remove the glass top currently on the tank to prevent water temperature build up or should I leave it on to prevent moisture from getting on the MH bulbs If I leave the top off, I am assuming that would increase water evaporation and necessitate more frequent water top offs). <I would remove the glass with either type of lighting> I am thinking I would need to ventilate the canopy-would I need 1 fan (moving air out) or 2 fans (moving air in and out) of the canopy? Would mounting the T5's in the canopy place the lights too far above the water (there is approximately 10" from the ceiling of the canopy to the top of the water and there is  glass top on the aquarium currently in place).  How often would I need to change the MH bulbs vs. the T5 bulbs and replacement costs considerations?   <Depending on the hours used, half to every year> I know, lots of questions, but like I said, I want to get it right the first time.. Thanks so much, M. Jacoby   <In all cases I would install a heat and light reflective barrier in the canopy (all surfaces) and fans for cooling... The choice you face, consider has another component and that is operational costs... the MH's utilize much more electricity. Both types of lighting will/would do... You must decide whether you want the challenges/headaches from the MHs... more algae growth, the need to monitor, adjust water chemistry... IF you decide to use organisms that can, will utilize their energy. I strongly encourage you to read over the FAQs files on marine lighting archived on www.WetWebMedia.com until you understand your options and their incipient benefits, drawbacks. Bob Fenner> Lighting for a 135 gal Boys metal halide I just purchased a 135gal tank and need lights and a skimmer would like in sump skimmer or inline. what type is going skim the best with the least amount playing around. << The bigger the better.  That is about all I can say.  I recommend seeing some skimmers in stores and checking some internet review sites (Reefs.org) >> next lights 72" HQI or standard metal halide I would like clams, corals and don't want to have to upgrade every time turn around. any help would be great << For a 135 gal I would probably have three 400 watt HQI halides, or maybe four 250 watt HQI halides. Also, I would have four 110 watt VHO actinics. >> thanks Darren <<  Blundell  >>

Lighting a Huge tank Lets say I built a aquarium 96" long by 48" wide by 48" tall. Is this even possible??) <Sure> out of plywood and glass according to the methods on www.garf.org. Would 8 96" VHO's be enough lighting to make this tank relatively bright and enough light for live rock and softies and polyps and Shrooms? <Barely... metal halides are best for this size, depth of system> If I made a tank to these dimensions, would (2) Berlin XL's Protein Skimmers each rated for up to 500 gallons be enough skimming? <Should be close... but I'd look into EuroReef, ETSS lines> How many GPH on an external pump would you recommend? <5-8kgph... look into Baldor-motored Sequence pumps... much cheaper to operate> And HOW would I heat a tank this big? With what type of heaters? This would sure require a lot of salt. Well, Thanks!, Adam M. <There are in-line resistant heaters of thousands of watts... You can find these on the Net. Bob Fenner> Upgrading DIY lights Hi all, I currently have an Orbit PC light system that runs (4) 65 watt lights (2 10,000k and 2 actinic) for a total of 260 watts of light. I currently have a 90 gal FOWLR acrylic tank and would like to modify my lighting. Do you think it would be possible and feasible to remove the 2 10,000k's and add two 175 MH's to the Orbit fixture. I don't have a problem with the DIY part of the project, but can these lights be put in the same unit like that? Would I need some type of  spacer between the PCs and the MHs? << I think it is a great idea.  Well worth the upgrade.  As for the fixture, never had one.  So I don't know if they will go well in there, you may just want to take everything out and make a new fixture.  As long as you added fans to keep it cool, I think you will be fine. >> Thanks Todd <<  Blundell  >>

Upgrading DIY lights continued Thank you for your response. Now I have more questions (imagine that?). The dimensions on the fixture or hood are 48" x 7" x 5" (LxWxH), and the hood is made out of metal. How far apart should the MHs and PCs be? << Oh about 3 inches from each other I would guess. >> I have a 4" fan on one end and a vent on the other. Also how close can the MH be to the metal hood? << I'd say the bulb can be quite close, but have a reflector behind it.  I'd add a second fan.  However, as a disclaimer I advise you to talk to an electrician or someone like that.  If you burn your house down I'm not to blame.  But if it were me, I wouldn't be worried. >> Thanks again Todd <<  Blundell  >> Need help with lighting Hello, I have just started up a 55 gal saltwater tank and was looking at getting some Fiji live rock. I was told I needed moderate lighting for this rock. My tank is 48" long. What lighting system would you recommend for this? <Mmm, what other life do you intend to keep? The organisms that are in/on, make up the LR can tolerate, utilize a wide range of light type, intensity...> I am not looking for anything that will break my pocket book but something that will help the polyps and live rock grow and shine. Pls help. My current tank hood is a perfecto hood with a single fluorescent light like 40watts. I am not planning on having any soft corals or anything fancy . thanks <You have a few options... but in terms of initial costs (for purchase) and operation (electricity and lamp replacement) I'd look into "boosted" fluorescent technology... on the low end, VHO... to power compacts... to T5s... Positions, arguments for all of these and even metal halides can be read through on www.WetWebMedia.com Bob Fenner>

Lighting for a 55 gallon Big Hellos To The Crew, I've wrote before with various questions and you have been great, I have an 18 gal. nano. The lighting consists of 80 watts PC's, 6700/10,000 and 420/dual actinics. I have various soft corals, xenia, mushrooms and polyps. They are doing well on 4.4 watts/per. gal. My question is, I'm starting a 55 gal. reef and want to leave myself some other options for SPS corals. It's a traditional sized 55 gal., I need to know about the watts per/gal. I have in mind a 4X96 watt (7 watts/ per. gal.) dual daylight and actinic or the 4X65 watt (4.7 watts/per. gal) dual daylight/dual actinic. I want to have enough light to do the little critters justice. There is a couple hundred dollars difference in price. If I kept to the species that I have now,  would the 4X65 watts be enough in the 55 gal. and if I went with the 4X96watts will it be too much?   The lights in question are both 6700/10,000K dual daylight and dual actinics. Would I be able to keep SPS corals with the higher end lights? The last question to you is about heat, the lighting system has legs and will sit above the tank with no hood or glass top, do you think the 4X96 watt fixture will have an impact on the water heating up? Thanks so much for your site, Jerry S. >>>Hey Jerry, First let me steer you away from the *watts per gallon* fallacy. There is no such thing. Would you light a 6" deep 100 gallon tank, and a 3" deep 100 gallon tank the same way? Nope! Rather, you need to be concerned about spread, and how much water the light needs to penetrate. 4x96 watts is far from being too much light for that tank. In fact, considering two bulbs of the 4 are actinic, you don't have nearly enough light for many corals. If SPS is your goal, than forget about the PC lights and go with metal halide. Two 250W double ended metal halide, or two 400W mogul bulbs will allow you to keep anything you want. Two 150W double ended bulbs, or 2 250 watt moguls will many critters to be kept as well, with the exception of the most demanding corals. If you are stuck with the PC's, then use 3 daylight and only actinic. You will able to keep a few SPS's like Montiporas, and less demanding clams like T. squamosa. Heating concerns are different with every tank, you'll have to make that determination yourself. Cheers Jim<<<

Lighting, heat Thanks so much for your reply.  I will do just that.  Do you have any suggestions about the heat?  My room temp is 72F.  Not sure why I cannot get my heat down.   Thanks!! <"green house effect", try removing one or both of the glass lids on the tank.  Good Luck. MikeB> Re: Light changes Thanks for the response.  With such a drastic change to the tank, should I introduce just 2 of the 4 bulbs for a while for it to get acclimated? <Yes, a good idea>   Will I see any other major changes in my water to be aware of?  Thanks <Perhaps some increased algae growth, a shift in the predominance of some of the Greens. Bob Fenner> Comparing heat between halides and pc Hi crew, I fired up my new HQI's the other night, and I want to thank you for all  the advice you gave me. << Good, I'm glad the advise worked out. >> I have no question tonight.  I just want to address any and all that  are considering halides.  I had power compacts over a glass canopy, and I  just upgraded to 2 X 250 10K HQI's.  My new halides produce LESS HEAT  THAN my old PC's. << Also good to hear.  I'm sure others will find this useful. >> Please do not let any water temp misinformation stop you from buying  these lights.  My temp has not changed, and the lighting is gorgeous.   << I too have HQI halides on my tank (30 gal) and I love them. >> James, RI <<  Blundell  >>

Some "Light" Conversation (Lighting Alternatives) Hi Crew <Hi there! Scott F. with you today> I am looking to upgrade my tank lights that I bought when I started this hobby, my first salt tank 2 years old, as they are very inadequate at the moment. <Seems like part of the normal progression in our hobby!> Tank is 36 inches long, 18 inches deep and 15 inches wide. My tank currently has some Mushrooms and Xenia. I plan to expand this when I have my new lights with large polyped stony corals such as Brains and Bubble corals. <Nice corals to keep; they are both beautiful and under-appreciated, IMO!> I do not plan on keeping Small polyped stony corals. I have read through your fact sheets on lighting over the last few weeks and its a very complex topic with many differing opinions. I wanted to bounce my plan off you and get your comments and hopefully the stamp of approval on my final plan. I don't want to waste money on a bad plan. <I can relate!> Well, first off, I need a new hood and I quite like the hoods supplied at http://www.arcadia-uk.com, of course the model would vary depending on the lighting selection. I have narrowed it down to 2 options: Option 1 Metal Halide Two 175w 14k bulbs metal halide bulbs Option 2 T5 Two 54W Marine Blue Actinic Lamp and two of the 54W Marine White 14,000K lamp Now the Metal Halide option supplies brighter and more intense lighting plus the ripple effect. I think, however, I would prefer the T5 option as it is cheaper, less hassle with the hood (I have 18 feet ceilings and don't fancy suspending the metal halide hood from them) Most importantly I think that the T5's will provide me with what I need for the corals I plan on stocking. So mostly it will be easier and cheaper for T5's but I'll have the lighting I need? <I agree that T5's may be a nice choice, given your animal selection and requirements. I am a bigger fan of metal halides, though, for a variety of reasons. The first reason is that they really do provide a lot of "bang for the buck", particularly in the 150watt and 250watt sizes, in double-ended formats. Lots of different spectra to choose from. I've seen some outrageously beautiful LPS tanks illuminated exclusively with 20,000k metal halides! The next reason is future flexibility. If, for some reason, the urge to move into SPS corals bites (don't ask me why- it just does...!), you'll be able to accommodate them with halides much more easily than you would with other types of lighting, IMO.  There are some great retrofit pendant/hood systems from manufacturers such as Sunlight Supply, PFO, and AquaMedic; well worth checking out.> What do you reckon to my choice in bulbs? <For LPS, I'd go for the aforementioned 20,000k bulbs or the 14,000k bulbs that you mentioned. Either will supply great light for your system!> Final point is that I have been using a condensation tray over my tank and under my lights. I have removed that today so there is nothing between the hood and the water. I am nervous about how much water will evaporate or dust getting in, etc., but I hope this will not be a problem? <I have run open-top systems for some time, with great results! You will experience more evaporation than you might have previously, but this should be predictable and manageable after a while. The bigger issue is acclimating your corals to the more direct light they will receive when you remove the barrier. If you acclimate them slowly (see Anthony Calfo's work on WWM on this topic), you'll see a remarkable change for the better over time.> Let me know what you think and thanks in advance for the top notch info service. John <Glad to be of service, John. Don't let my prejudice towards halides overly influence your decision, but do take them into consideration! Best of luck! Regards, Scott F>

Lighting Hey fish-gods- <Mmm, maybe demi-gods> I was just wondering...I have 50 Watt Halogen tack lighting in the room my 75 gallon reef tank is. Does it affect my tank that sometimes when the light goes off, these lights in my room remain on? <Actually, better that there is some outside light on... rather than abrupt changes from light to dark in the tank> These lights are approximately 5 feet above the top of the tank, so I would assume that they don't do any harm. but my fish remain pretty active until they are off, and the corals deflate from daytime position, but do not fully inflate their nighttime tentacles until these lights are off, so I thought I might be harming the inhabitants from these house lights remaining on. <Good observations> Any info would be great. Brett Chisholm <Humans are much more subdued in their responses to changing light, time periodicity... aquatic life by and large much more attuned... it can be quite bright in shallow reefs at night time... Bob Fenner> Lighting I am so confused concerning lighting needs.  I guess it's the term "watts" which has me confused. <Easy to be confused here... watts can be a measure of consumption of electricity (volts times amps...), equivalencies in production of photonic energy per consumption... or an indication of neither> When speaking of a Reef Tank, are "watts per gallon" considered the equivalent of incandescent watts, normal output fluorescent, HO, VHO, or PC fluorescent? <Mmm, no... on two counts... the issue of whether one is speaking of consumption/production and the quality of light, its physical characteristics (e.g. "punching" potential to depth, selective absorption of wavelengths, spectral mix, "looks", what sorts of livestock you intend, what you want to do with them (keep them alive, boost color, growth, reproduction... Functionally and aesthetically, the "watts per gallon" is only an approximation, useful yardstick... for given groups of organisms and lighting technology.> I am planning on converting a 360 gallon freshwater tank to a reef tank.  8' long, 2' wide, 3' tall. <For this depth you will very likely want to utilize Metal Halide technology.> The freshwater, fish only tank currently has four 48" 32 watt NO fluorescents.  4 x 32 watts = 128 watts NO fluorescent. 1 watt NO fluorescent = 4.54 watts incandescent, therefore 128 NO fluorescent watts = 581.12 watts incandescent My calculations tell me for a 360 gallon Reef tank I need approximately 1800 watts to achieve lighting of 5 watts per gallon. Do I need to add (just as an example) 52.25 more 48" 32 watt NO Fluorescents lights OR do I only need to add 8.38 more 48" 32 watt NO Fluorescent lights? <Mmm...> (In actuality, I won't be adding just more NO lights, but I'd be adding PC lights (PC lights have the equivalent of 1 watt PC = 8.33 watts incandescent).  I'm just using NO as an example to figure out my question.) <If all you intend is non-photosynthetic life here, I might go with something other than MH (or even some natural sunlight), but if you will keep light-using livestock, the metal halides are your best bet currently> It all boils down to which kind of watts the "watts per gallon" rule pertains to. Thank you for any help you can provide to this question. Vicki Fletcher <Thank you for writing. We have much more on marine system lighting issues archived on www.WetWebMedia.com Bob Fenner> Lighting a 55 Howzit guys, great site and it's for free!!!!! I want to know what the best lighting for my tank would be. I have 4x30watt fluorescent bulbs but somehow know it is not sufficient. I have 2 H. magnifica anemones. they seem to be doing fine (sticky, eating, "walking" <Should NOT be moving...>) they are not the full size they can be though. the white one seems to becoming yellowish too but the purple one seems fine. are my lights sufficient? <On the very low end yes... but could be doubled, trebled in intensity positively> the tank is standard 4 foot i.e. 1.2 m long. saw in the faq that you don't recommend MH lighting for a tank this size. please give me an indication of the quantity of fish to be kept as I have a figure of 5 in my head for some reason. I have a standard 3 foot for the sump. <Actually, due to the depth/shape of these tanks (22 inches before substrate added...) Metal Halides are advisable. Bob Fenner> thanks a lot

Lights Hi, how are you? <Fine, thank you> I was wanting to know what kind of lighting you would recommend for my 150 gal. (tall). I keep fish and quite a bit of live rock, so I guess you would say a fish only tank. I have looked at the Coralife Lunar Aqualight with the 96 watt 10000 k daylight and the 98 watt true Actinic 03 blue 420 mm compact or should I spend the money for the Metal Halide, are they worth the money in my case? <Not, IMO... more intensity, and more likely to cause nuisance algae growth...> Do I need to run a UV filter with either one of these lights? Your opinion would be greatly appreciated. Thanks, Nels <None needed. Bob Fenner>

Desk lighting the same as aquarium lighting? - 11/22/04 Hi! First of all, thank you very much for your fast reply. <You are absolutely welcome!> I still have some questions on illumination. <Sure thing> The lamp I have is not actually meant to be an aquarium lamp (rather a desktop lamp), <Ohhh. Well, very likely this bulb is too much in the red/yellow/orange spectrum and of limited to little use in the photosynthetic process.> and it has a 11 Watt power saving lamp (Osram Dulux s). <I would use this if in a fish only situation. It is NOT going to benefit most if not all photosynthetic animals> What is the difference between such a lamp and a power compact lamp of the same wattage? <Spectrum for sure, PAR (Photosynthetically Active Radiation) output as well. Also, the intensity (wattage) is a bit low for 6 gallon tank. 11 watts/6 gallons=1.85 watts of usable energy intensity, not quite enough. There is quite a bit of information on lighting aquariums (nano or otherwise) in our articles/FAQs section.> Is the light spectrum of the Osram lamp ok for a nano aquarium? <In my personal opinion, no. Again, use the internet as a tool, grab few books and periodicals where you can. Koralle is a great and informative magazine that I enjoy and find very informative. Thanks for participating here at WetWebMedia, Ana. ~Paul> Thanks again. Ana

Aquarium lighting 11/21/04 I am in process of building a room for a 200 Gallon Tank.  I currently have a 44 gallon tank that is growing soft corals and has only one fish a six line wrasse.  I also have three emerald crabs and approximately 15-20 small hermits. I currently use three VHO (36 inch, 1 actinic and two white light)) <do resist all crabs in the reef tank for best long term results. As they get older/larger they are at least a small threat to other desirable reef invertebrates. Crabs are generally opportunistic scavengers/predators... particularly the Emerald crabs in this case> My question concerns some reading on new solar lighting using a highly reflective 36" diameter "solar tube that mounts on the roof and brings 97% of the light to the room.  I have heard that natural light even on a cloudy day is better than anything we build with these "hot" lights. <generally so, but many such tubes have UV filtering glass/acrylic... this is not ideal for reef invertebrates> Can you comment on this?  It is my intention to have two tubes feed the light to the tank. <it will be well worth the addition, indeed. Natural sunlight is incomparable. Anthony> Lights Hi, how are you?<Good and you??> I was wanting to know what kind of lighting you would recommend for my 150 gal. (tall). I keep fish and quite a bit of live rock, so I guess you would say a fish only tank. I have looked at the Coralife Lunar Aqualight with the 96 watt 10000 k daylight and the 98 watt true Actinic 03 blue 420 mm compact or should I spend the money for the Metal Halide, are they worth the money in my case? <If you want coralline algae to grow on the live  rock then I would go with the metal halides.>  Do I need to run a UV filter with either one of these lights?<I strongly recommend a UV. Sterilizer in a fish only tank.  It helps control the spreading of disease and algae.> Your opinion would be greatly appreciated. Thanks, Nels <Hello, I think either lighting set up would be sufficient for your tank.  If you want the coralline algae to grow, I would recommend using the MH's otherwise I would stick with the Power Compacts.  MikeB> Timing is perfect??? Good evening Crew, <Hey Alex, MacL here with you this evening>   How many hours should my tank be in full spectrum lighting??? <I keep my tank on full spectrum for 12 hours.> I just bought the awesome Orbit 1020 20 inch  power compact for my nano, and I tell you guys is the most beautiful power compact I have ever seen!!!<Sounds amazing, congratulations> And has a full 24 hour lighting system to go with it COOL!!! Thanks for you time Lighting Questions : T5 & MH Hey guys! :) I have a question about lighting. I've been looking at the Sun Supply fixtures; two in particular. One is 8 x 39w T5's (4 day/ 4 actinic 03), the other is 2 x 150w MH 10000k and 2 x 39w T5 actinic 03's. Both come with all ballasts and appear to be nice fixture, though I do not know anyone that's personally used one.  I have a 70g reef that is intentionally understocked (5 fish, the largest is maybe 2"). I have some various soft and LPS corals (Xenia, brains, Fungia, Frogspawn, Hammer, some Shrooms, etc). The tank is 36x18.5x30.5.  I'd read somewhere that 150w MH's may not be adequate for a tank 30.5" tall, but was unsure hence my asking :) <This is not a cut and dry question.  The corals that you listed will do quite fine under either of these lighting schemes.> I have no intention of ever delving into SPS corals as they don't really interest me; I guess I just find the LPS's more eye-pleasing.  <Don't say that like it's something to be ashamed of!> So in short, I'm just looking for some input on lighting recommendations and what you guys think of the two items above. <With your preferences, either scheme will serve you well.  In the long run the MH fixture may actually have cheaper lamp replacement costs.> Thank you very much all your time and the wonderful site! -Jeff <Glad to!  Hope this helps.  AdamC.>

Lamp colors and Refugiums 11/9/04 I have a couple quick questions.  I'd like to know what the difference is between the 7100k lights and the actinics.   <actinics are a single wavelength (around 420 nm for some) and 7100K lamps are a full(er) spectrum akin to daylight. This latter lamp being much better for PAR for corals> I know the actinics are specific to 420nm which I've heard doesn't do much for photosynthesis, however, great for aesthetics.   <Doh!... I should read ahead. Yes> The 7100k lights I've seen out on the market look pretty similar in color to the actinics, but I've been told they're much better for photosynthesis.   <correct... do look at PAR values in charts and analysis... articles by Sanjay Yoshi for example> Another confusing thing is that a 6700k looks yellow and a 10k looks more white but a 7100k which is in the middle of the two looks blue??   <different brands and even interpretations by individuals (we all do not see color the same)> I just would like to know what the deal is with all this. One thing that I've been looking forward to is the next book in the natural aquarium series.  Could you tell me what the schedule of releases are?   <we are getting into layout and pre-press now... hoping for the first of a 2 part-volume on Reef Fishes for early next year> I've learned a ton from just the invert book.  It's inspired me to get a refugium.  I don't have one yet but it's in the works.  BTW have you had any experience with the ecosystems refugium method? <yes, and many refugium styles> Is it really that much better than a standard refugium growing less dangerous algae.   <of its many benefits I would not count that as one. Water flow is more of a factor here> I've also become a firm believer in the quarantine tank as well. <this is a critical lesson... it will take you far> I tell all my customers to quarantine quarantine quarantine!   <all will succeed better for it. Thank you for this effort!> Well this has turned out to be quite long so I'm  going to cut this short.  You guys are great thanks a mill. Chris aka fishtank <best regards, Anthony>

Lighting Lux measurements Hi , thank you for this opportunity. My question is how much Lux  is in the 400W XM 20K bulb and 250 Radium 20K Measuring not under water (my meter is not submersible and only up to a 3000 Lux.) << Wow, great in depth question.  The best thing I can say to do is to read the works of Sanjay Joshi, as he has more knowledge and publications than any of us.  For example....>> http://www.advancedaquarist.com/issues/july2003/feature.htm http://www.advancedaquarist.com/issues/august2003/feature.htm Thank you . Russell. <<  Blundell  >>

Light Penetration I realize that so many factors affect light penetration.  I am curious about one factor.  Reflection from the surface water of the aquarium.  Has anyone experimented with using submerged viewing lenses.  The idea occurred to me because I am a diver.  When you are waiting to drop and you can't see against the reflection from surface water you stick your mask in just deep enough to break the plain of the surface water and everything becomes perfectly clear.  Would a viewing lens between the light source and the water surface of this type allow for more light penetration?  Has anyone thrown a Lux meter against this type of idea?  Do you know what I mean? You could build an insert that just breaks the plain of the surface of the tank. It will filter UV as well.  Once side is dry and exposed to the light source and the tank side is kept wet.  Like a glass bottom boat.  Don't laugh... What are your thoughts? Thanks Mike >>>Hi Mike, I haven't tried it, nor do I know anyone that has. Give it a go and get back to us. :) Remember you still have a reflective surface between the bulb and the water with your idea. Cheers Jim<<< Lighting I have a 200gal tank, 72" long.  For my light fixtures I have a Coral Life MH Fixture that Holds 2 175w MH and 2 48" Fluorescents, then I also have 2 additional MH fixtures that will hold 175w MH.  So in total I have the Ability to have 4 MH and 2 48" Fluorescence.  In this tank I am wanting to have probably Mushrooms, Polyps, Leathers, and things like this. I am going to have some were around 200-300 lbs live rock. Is my lighting sufficient or too much (meaning should I use all the fixtures), >>Its more of a personal choice. I would run the 4 MH, then add flour actinic for color. With the corals you want to keep you should have no light problems>> and what kind of MH bulbs should I put in my fixtures, 10,000 k, 5,000, ???. >>Again, that is really a personal preference - except the 5k. The lowest reefers use is 65k and most find that too yellow. I would go with 10k or 14k with actinics, but that is just me. :D>> Also, I am planning on having the fixtures at a height so that the Bulbs are about 12-20" off the water, this is correct right? >>Most seem to go with 6-12 inches, 20 seems high.>> Thanks much for all the answers you can give. John M. >>Hope they help, Rich>> - Equipment Questions - Hi crew- I have been both researching your site and asking you direct questions, both have been invaluable.  I appreciate them both, as I'm sure countless others do also. The background info - I have been upgrading my entire 90 gallon reef system. I have already automated the evaporation top-off, added a closed loop with an 1800 gph pump to replace my 3 powerheads, added a 30-gallon circulating reservoir, and basically made it easier for me to keep faithful  water changes. The last 2 pieces of equipment I'm about to purchase are the halide system and the skimmer.  I've decided on a 4'- dual 250w HQI 13K halide  hood, with dual 54w T5 actinic, all made by "Won Brothers". Does this  company provide reliable equipment and good bulbs? <I honestly don't know... have never used their equipment before. This question might be better posed on one of the reef forums where you'll get a sample size greater than one.> (I shied away from  Hamilton after I read that their lights are fair at best)? My skimmer choice is a TurboFlotor 1000.  I would like your advice/opinion of these two products. <The Aqua Medic skimmers are good products - I'm sure it will treat you well.> I have a 90 gal tank, and will be keeping a lot of LPS  corals (frogspawn, flowerpot, xenia, etc) with some SPS corals, and 1 or 2 clams.  My tank is now open top. How many watts per gallon?? - (I'm kidding of  course).  Thank you so much for your time and help. James, RI <Cheers, J -- > Color temps of bulbs hi, could you just have a higher Kelvin instead of getting VHO bulbs << No.  The Kelvin rating is the basic number for the color of the bulb.  It is a little confusing because basically two white looking lights could both be 10000k.  But one could have more green light, or more red, but since they both look white they are 10000k.  A 20000k bulb looks very blue, but strangely enough may have less total blue light than a 10000k.  Very difficult to understand.  In general a 10000k is a nice white looking bulb, good for coral growth.  A 20000k bulb is blue looking and good for coral color. >> <<  Blundell  >>

Removing or drilling through the center tank brace Hi.. thanks for any help you can give me with this. We recently switched from a 75 gallon reef to a 90, and the tank is made by All Glass. We have a Coralife pc lighting system with 3 moonlights. The problem is, the new tank has a plastic bar down the middle, to keep the glass from bowing, and that blocks the center moonlight from shining into the tank. << Wow, first time I've had this type of question. >> Would it be okay to drill a 3/8 inch hole in the center of the plastic to allow the moonlight through? << Well here comes the liability problem.  If it were my tank, I'd drill it.  Or, find a way to move that moon light.  Now I'm sure that would void any warranty with that tank, and I know many people will think I'm nuts for having even said it is an okay idea.  But I'd do it. >> Will this cause problems with the construction integrity of the tank? << I know some local stores in my area cut out the center braces on tanks, and replace them with clear acrylic braces.  They do this so that you don't get shadows from the halides showing in the tank.  But since moonlights are cheap to make and common to find, you could just add another moon light in the tank. >> Thanks again, Marcye <<  Blundell  >>

Tank Lighting question Dear Crew, <hey Steve, MacL here.> I want to start out by saying I really appreciate your website and have had my head buried in it for weeks.  It has answered many of my questions and now I'm starting to form my own opinions. (oh no)  I'm new to reef tanks and the information is endless but I'm taking it one step at a time.  I'm getting all sorts of new toys and it's a blast. But it seems I'm at that in-between place with the depth and length of my tank..  I sent this questions a few days ago and have not heard back, a would really appreciate your opinion and thanks <We've been adding more staff so this will probably be a repeat answer Steve but let me address what you put below.> again......Steve    Tank 60x24x24" 150 Gallon,  Preferred lighting would be 2-Hamilton 150w 10k HQI ReefStar Pendant's and 2-96w blue actinic's.    New tank set up and the inhabitance will be mushrooms, leather's, polyps, anemones, LPS corals, sponges, and clams.  <The big thing that requires lighting in your list is the clam. They require more lighting then the others on your list.> I have read that 1-175w MH lamp per 2' x 2' with a tank depth of  20" to 30" deep will do fine for just about anything, and as you can see I have 1 extra foot.  After reading some of the FAQ's looking for my answer I feel that I'm not EVEN providing enough light compared to what I have read that others are using.  Do I add another 150w Pendant? <I can tell you that I have a tank depth of 24 inches and I don't feel that I have sufficient lighting for a clam with 175's no matter what my spectrum. I would step up to 250's.>  This will cost more in hardware and electricity, or move up to 2-250w Pendant's which I'm sure will be enough but at the cost of a higher electric bill, I live in CA. Or is this enough for my planned inhabitance?  <Steve if you look around I think you will find some more economical 250's  Good luck and let me know what you decide to do. MacL> Thanks Steve Ice cast dimmer I recently purchased a used reef system out of the classifieds.  With all the equipment the individual was giving me was an Icecast dimmer.  The lights on the tank are VHO's with an Ice Cap 660 ballast.  Unfortunately, there are no instructions with the dimmer.  I have tried to hook it up, and it shut the lights off, and turns them on, but doesn't really dim the lights at all.  I have searched the internet, and have not found the company, "Digital Oceans".  Can you help?  Thanks in advance.   >>Its not Icecast, its Icecap. Try www.icecapinc.com - I believe they have downloadable manuals. Rich>>

Throwing Some Light on Lighting... Hello there crew, <Hi there! Scott F. at your service!> Thank you guys for all the valuable info you've given me!   Once again I'm stumped and need your guys help.  I'm looking to buy a MH lighting system for my 70g tall tank (36x18x24) with a 5-6" sand bed.  I'm looking to keep clams and SPS corals along with a Heteractis Magnifica (beautiful but demanding I know).  I've more or less decided on dual 250w 10k Ushios but can't discern what is the big difference between the regular socket type bulbs and double ended HQI bulbs.  Either way both will run off the appropriate dual PFO ballast.  Both of  them will have reflectors and a glass cover also.  My big question is are either of them more powerful than the other?  I've read that HQI's can have higher PAR values than regular bulbs.  I've also heard they have a bluer output than traditional bulbs of the same wattage and cooler temp.  They also require a digital ballast from what I've come to understand also.  That explains the higher cost of the HQI ballast I suppose.  I like the 10k color spectrum when used alone and just need to know some of the Pros and Cons of the two formats (HQI vs. Standard). Sincerely,   Chris  AKA  ~ fishtank ~ <Well, Chris, there are many schools of thought on this topic. Some studies have indicated that double-ended (HQI) bulbs do yield higher par values than some comparable mogul bulbs. I tend to favor the HQI bulbs because they are also more efficient from a power/performance aspect. Double-ended bulbs do need to be run on electronic ballasts, of course, and they need to be kept in enclosed pendants (like PFO, Sunlight Supply, Aqualine, Giesemann and others offer). They are more expensive than mogul bulbs, in most cases. If it were me, I'd go with the 250 watt double-ended Ushio or Aqualine bulbs in a quality pendant-ballast combo. Some people tend to think that the Ushio and Aqualine 10ks are too "yellow" if run "unsupplemented" (i.e.; without VHO actinics). Some of the newer bulbs that are proving popular from both an aesthetic and performance standpoint are the 14k and 14.5k bulbs offered by companies like Giesemann, Hamilton, and Aqua Connect. The AC's are not cheap, but they are beautiful from an aesthetic standpoint. Good luck! Regards, Scott F.>    Lighting Question - how much is enough? 10/11/04 Tank 60x24x24" 150 Gallon,  Preferred lighting would be 2-Hamilton 150w 10k HQI ReefStar Pendant's and 2-96w blue actinics.    <very nice> New tank set up and the inhabitance will be mushrooms, leather's, polyps, anemones, LPS cor ls, sponges, and clams. <all good except the anemones mixing with sessile cnidarians/corals... unnatural and impractical to the point of being a high risk (read the disaster stories in the FAQs). Please do not mix corals with anemones> I have read that 1-175w MH lamp per 2' x 2' with a tank depth of  20" to 30" deep will do fine for just about anything, and as you can see I have 1 extra foot.   <its really just a guideline... you can keep your lower light LPS and Corallimorphs on the fringes here> After reading some of the FAQ's looking for my answer I feel that I'm not EVEN providing enough light compared to what I have read that others are using.   <I disagree and think you are fine for the groups you've mentioned> Do I add another 150w Pendant? <if you want to keep higher light species, yes> This will cost more in hardware and electricity, or move up to 2-250w Pendant's which I'm sure will be enough but at the cost of a higher electric bill, I live in CA. Or is this enough for my planned inhabitance?   Thanks Steve <no worries... pick your lights after you have chosen a very specific species list. Narrow down more from the general groups you've mentioned thus far. Some mushrooms like Ricordea like high light, most others fare better with much lower light, etc. Anthony>

PAR value and lighting source 10/12/04 Can you please tell me what PAR value is when it comes to lighting? How does it change with Kelvin and how does it change when comparing PC to Metal Halide??? Thanks Jeret <Wow!  Not such a simple question.  PAR is Photosynthetically Active Radiation.  The chlorophyll in zooxanthellae can only use certain wavelengths of light.  While measurements like Lux or lumens measures total light output, PAR measures only that part of the spectrum that is useable for photosynthesis. Since PAR depends on both total intensity and spectrum, it is very difficult to generalize about different light sources and unfortunately, manufacturers don't tell us what the PAR is for their lamps.  Authors like Sanjay Joshi and Dana Riddle have done excellent work to report the PAR values of different lamps and light sources.  Google searches on their names will lead you to their work. Some generalities can be made...  Watt for watt, cooler (bluer) lamps tend to have less PAR than warmer (yellow/red) lamps.  This is because so much of their energy output is concentrated in a narrow band, while warmer lamps tend to have output over a wider part of the spectrum. It is hard to compare between Fluorescent and MH since the spectra can be quite different, but both technologies produce a similar amount of light intensity per watt.  In other words, 400 watts of fluorescent produces about the same total light as 400w of MH, it is just more spread out. Many aquarists forget that they can use much less light if they use it more efficiently.  Using carbon or ozone to maintain water clarity, using highly efficient reflectors and keeping them clean and running lights as close as is safely possible to the water all will dramatically improve the amount of light that reaches corals.  Following these practices would allow many aquarists to use significantly less light to achieve the same PAR reaching their corals.  FWIW, PC lamps have an inherent inefficiency since they are constructed of two adjacent tubes.  A lot of the light from each tube shines into the adjacent tube instead of being reflected into the tank.  Best Regards!  AdamC.>

Lighting Issue Hi WWM Crew, <Hello, Ryan with you today>    We just had a quick question for you. <Surely> My husband and I are looking at upgrading our 75 gallon tank and we are looking at an acrylic tank.  Its dimensions are 36" tall, 36" long, and 18" wide.  We would like metal halide because we would like to have clams and polyp corals.  We have found that it would be cheapest to have a pendant with a single metal halide light, as opposed to some of the combination fixtures. <Cheaper, yes, but the light will not be nearly as even across the tank.> What would you suggest in terms of wattage and Kelvin? <3-6 watts per gallon, depending on the animals you intend to keep.> Is it necessary to have supplemental actinic lighting or is there a middle-of-the-road Kelvin color that would provide an adequate spectrum? <Yes, something higher on the scale will have plenty of blue for most tastes!  Cheers, Ryan> Thank you, Damon and Jennifer

What Kelvin rating for a 125 gal? Hi Blundell (and Crew), This is Diane again (but first let me thank you for being such a tremendous help with redoing our 125 gal. tank.  I have an early New Years' Resolution which is to ask, or read, first!  (After this one, our most costly single item of course, lol.)  The background is that this was a FOWLR tank with three UG filter plates run by dedicated PHs with large grain crushed coral that I removed to take out the plates and replace with DSB. Oh my, the life I destroyed in doing this!  << Yeah but it may be worth it in the end.  I've just capped off or pulled out the undergravel tubes before, and left the plates in as a plenum. >> I did not know, or notice, until too late the gravel was full of little Starfish and crusty worms and all sorts of great little creepy crawlies. << That is why so many people buy their sand off of an existing tank. >> The UG plates were swarming with them and these I saved but…. Anyhow, now I have a 5" to 6" DSB made up of approximately 2" of the original CC, 2" of crushed aragonite, and 2.5" of live sand from Tampa Bay Saltwater.  Also, approximately 100+ lbs. of live rock.  I really have no idea but it's a lot and pretty much fills the center of the tank end to end, top to bottom. Inhabitants are: 1 two inch Cherub Pygmy 1 two in. Six-Lined Wrasse 2 3 and 4 in. Scissortail Darts 1 lg. Black Brittlestar (and several smaller ones that came on rock and sand) 3 Cukes And a bunch of blue-legged hermits with a mix of Trochid and Cerith snails. There is also a Red Spotted Sand Perch that is coming out just as soon as I figure out how to catch him amongst all that rock! The only other fish still waiting to go back in is our Coral Beauty but there is no hurry as I want to give Pygmy time. Now, finally, to my concern.  We purchased from MarineDepot a 72" light hood with three 175 watt, 5500kMetal Halides and 2x96 watt blue fluorescent/power compact bulbs. << That will look quite yellow to most people.  But will grow corals pretty well. >> I thought that gave me 712 watts over my tank but I just read that I can't count the wattage in the blue bulbs so I only have 525 watts.  I had already been looking to change the lights after doing some reading but I now find I can't up the wattage of the MHs without buying whole new ballast!  However, I can up the Kelvin, but I don't know if I should go with ten or twenty K and then possibly change out the PC blues with two 96 watt 10000k PCs.   << I would keep the pc's as blue/actinic lights.  I would probably switch the halides to 10k. >> I really hate to admit this but I also have a Green Star Galaxy Coral, at least it looks like a Montastrea Annularis according to Axelrod's Corals for the Mini-Reef (before I got Bornemann's book, Aquarium Corals).  It's beautiful and I have had it about six months.  These are the type of corals I want, if possible, but I also like Leathers and Xenias and clams so what do I need to do with my lights? << Well leathers and xenias are not a problem at all.  As for clams, I think you are okay if you keep them way up high. >> I have spent hours reading but it gets confusing (to me) and sometimes seems contradictory and I forget what I have already read and I only have two days off a week!!! Can you please help me again?  I DO want personal opinion! << Stay clear of the clam for a while.  Everything else should be okay, but I do think 10k halides will look better. >> I don't want to have to keep changing everything and I want what's best for our animals. (A lot of "I wants" in there huh?) Also I don't know anyone with saltwater tanks to look at and if I going to take anyone's opinion/advice, I would just as soon it was someone I have trust in with nothing to sell me.  The filter system on this tank consists of two Fluval 404s with Kent Reef Carbon and an Aqua Medic Turboflotor 1000 HOT skimmer.  It also has two 400gph PHs and three 370gph PHs with these really cool little whirly-gigs on them that rotate 360 degrees, breaking the surface of the water on each pass! These are temporary, until we get a single large pump (sump?)…(fair warning here, I WILL be back.)  The water parameters are, according to Aquarium Systems' Fast Test/Sea Test:  pH 8.0, am. 0, nitrites 0, nitrates 0, Alk. 3 to 3.5 mEq/L, calcium 400 or a little higher (god I have stared at so many color charts lately I don't trust my eyes anymore (ten aquariums)) And all I will be adding down the road will be shrimps and small docile fishes such as gobies and Firefishes.  And I'm done. lol.  Thank you so very much for all your time and effort, I hope someday you will know how much you are appreciated by all of us out here because there is no way to put it into words. Diane and Tom in LV, NV. << Nevada!  Well heck you have a club right there www.lvmas.org or is it .com?  Can't remember.  Anyway I stay in close touch with that club as I am just 5 hours away.  I'm sure they can be of help to you as well. >> <<  Blundell  >> Using sunlight... Hello Bob, I had read your sites many articles and find it to have very reliable advice. And for your site to acknowledge the high mortality and for those to remember that reef creatures are living beings and not just ornaments is commendable. >>Rich here...Thanks!<< Now my comments....I have found the best lighting to be sunlight. Why is real sunlight almost never recommended? >>Mostly because it is inconvenient! Most people want their tanks in their homes and arranging things so the tanks always gets enough sunlight can be difficult and expensive.<< If temperatures are controlled through a chiller or room air conditioning then nothing is better, more natural then the sun. And free!  Anemones, corals develop a brown tinge they never get even under intense halide. And I noticed they are more "meaty". like comparing house plants and thin leafs to outdoor plants and there much more tough leafs. What is better then looking at my Firefish hovering over healthy corals as sunlight streams down? And my Plexaura gorgonians? wow!  Fuzzy! And really brown. >>Sounds great - got a link to any pics of your system?<< And with sunlight corals in out-of the-way spots do fine. The shade is natural and still provides light unlike a bulb lit aquarium where shade is death. Look at all the reef photos on the Internet and the glaring contrast of the lit areas to the shade areas-not natural I believe far more aquarist should use sunlight. Plenty of the reef tanks featured are owned by affluent hobbyists. If they only new how much better there reef tanks would be placed in a greenhouse or attractive sunroom or, like my low income tank by a large sunny window. Again I have heard all the arguments--over heating, change of sunlight due to seasonal change, etc. All can be dealt with. If a chiller can handle thousands of watts of halide.... And the animals love the slow lighting of sunrise and sunset--no shock! There are a gazillion aquarist's who live in the sunny west coast and down south. >>I live on the west coast, and sadly, lighting my tank with the sun is just a logistical nightmare. << I do keep a 15 watt grow bulb for show and I can see using actinic for the same reason-or cloudy days. And that reminds me, for us here the corals put up with cloudy weather just like they do in the tropics during storms or rainy season. They just wait until the sun returns. Someday I would love to build a sunroom or lean to greenhouse with the reef tank featured. An anemone tank would be spectacular. thanks Adrian Escoto Lights for a tank in the wall Hello Crew!!! << Blundell today. >> And thanks to all of you for so much excellent help and information!   I have a question myself.  I have an acrylic tank (approx 200gal) I am building into a wall.  The back of the tank will be in a room dedicated just to the equipment and to allow easy maintenance (complete with utility sink, floor drain, etc).  << You will be so thankful you did this! >>  My question is on how to best mount the lighting.  I had been thinking of using a sheet of plywood suspended over the tank by chains.  << I like not having a canopy, as you are planning.  Then I like having supports sticking out of the wall.  Then I mount the lights on a plywood sheet or something like you are saying.  Then I just slide it into place on those support struts.  Not sure how to describe this.  You know those shelves you can buy at Shopko where you hand the metal rails on your wall?  Then you can make the shelves as tall or short as you wish?  Something like that.  It makes it great to just slide off your lighting and lay it on the floor to change bulbs and clean glass and stuff like that. Although some people really like having lights on a pulley system to lift up when working in the tank.  Pulley systems scare me holding those lights above my tank. >> I could then have a set of shorter chains so I could just lift the front, back, or entire board up to the higher position for easier maintenance.  (The section above the tank will swing up to allow access from the front).  I could mount all lights and reflectors to the plywood.  However, I read in many of your FAQ's about UV filters.  Since it is all in a room behind the tank, do I need to worry about that? << Depends on the bulb.  For the most part I say "yes" get a filter.  I also like having the glass filter as the glass is easier to clean than a bulb. >> Instead of just a board, should I build a box with the bottom being composed of something that would act as a UV shield?  I would then have to cool the box with fans, correct? << I don't like the box idea, but do like the idea of hanging a piece of glass below the bulbs. >> Since the original plan was just a boards (maybe with sides, but still open to the room air) I thought to avoid having to worry about any cooling.  Just wondering if my original plan would still work, and even if so, if anyone has any ideas that would be easier on maintenance.  Appearance is not an issue since it is all hidden in the room behind. Hope I explained what I was thinking well enough to be understood :) << Hope I explained well what my opinion on answers would be. >> Thanks for any ideas or corrections you can give me!!! Frank <<  Blundell  >> Lighting a 180 gal I am new to the saltwater hobby.  I currently have a 180g oceanic 72x24x24 on an oceanic stand with an oceanic wood canopy.  I have a large sump 900gal/hr and a downdraft skimmer powered by 500gal.hr pump.  Originally planned to be fish-only tank but becoming hooked on live rock and looking into corals. << I would definitely have live rock even in a fish only set up. >>   Current lighting is 4 40w flourescents(2 actinic/2 blue).  I would like to upgrade my lighting to 3 150w MH and 4 96w blue PC, but....my concern is heat and space under the canopy.  << I understand your concern, but even the proposed lighting is still not that high of power.  So I would definitely make that upgrade (at least that much). >> The oceanic tanks have a glass center brace and I'm concerned about cracking it. << I don't think you'll crack it.  Many people and local stores are now cutting out that center brace and replacing them with a clear acrylic brace.  That way you don't have the shadow from the halide, otherwise you can't but a bulb above it.  I'll warn you this does of course void any warranty on the tank breaking. >>  how much room do I need under the canopy?  How much air flow? << Not sure about room, but the amount of airflow is never too much.  So when in doubt just add more fans. >> retrofit MH suggestions? << None, but I'd look at a set up with two 250 watt HQI fixtures instead of three 150's. >> I have been looking at Coralife's Aqualight pro HQI 72" model-I could take the very top of canopy cover off and leave the 5 inch  canopy base on the tank leaving the top open to air, and fitting the Aqualight pro on stand legs on the inside trim of tank. << Excellent idea. >> this would put the lights 6 inches off the glass brace and still would-be generally pleasing to the eye.  good idea? bad idea? better ideas? skip MH and just go PC??? << Oh don't skip the halide.  You'll be happy you have them. >> <<  Blundell  >>

Lights for 92 gal corner tank I need some input on lighting designs for my 92g corner tank. I've decided to upgrade from my 2x92w PC lights. I think I can ask my father-in-law who's very handy to build me a hood as a holiday present. << Can't think of a better gift. >> Being that the tank is in the shape of a quarter circle, I thought of two possible ideas on how to light it: Plan A: Three 175w MH bulbs arranged in a triangle plus two 96w PC actinic bulbs (not sure where those should go. Any suggestions?), or, Plan B: One 250w MH bulb in the dead center and three 96w PC bulbs in the shape of a triangle around it (Should all three be actinics? Other combinations?). << wow, tough choice.  I'd probably go one 400 watt in the middle with the three pc's around it.  Otherwise, the idea of 3 175 watts is appealing, but if you do go three bulbs, then go with 3 150 watt HQIs. >> Being that I am completely in the dark (no pun intended) about Metal Halide lighting, I welcome any and all suggestions as to what to buy (i.e. what manufacturers, what components, etc., etc., etc.). << I'd probably try for two 250 watt HQI (double ended) bulbs and fit as many pc's as you can around them. >> In regards to the interior of the hood, what is the recommended finish to use? << I use polished aluminum as a reflector, and don't coat the inside wood at all. >> What size, and how many, fans? << A couple good sized fans.  I know that isn't the answer you want, but I just buy the big computer fans from Radio Shack, so I don't know how big they are. >> Should I be aiming for the lighting to be eight inches above the tank or perhaps higher? << Certainly not higher.  The closer to the water the better. >> If there's anything that I've forgotten to consider please let me know. I welcome any, and all, comments, suggestions, thoughts. And, Ummm donations. << You'll need reflectors in there somewhere.... I too am looking for donations. >> Thanks in advance for your assistance. Sincerely, Lonnie <<  Blundell  >>

Lights for a 90 gal It is a 90 gallon << That makes four 65 watt bulbs over a 90 gal.  That doesn't sound like very much light at all.  I use to have four 65 watt bulbs over my 30 gal, but decided it just wasn't near enough.  I would look into upgrading the lights for a reef tank system. Blundell >>

Lighting a 90 gal Sorry about all the questions on the same subject. But I do value your opinion. I am looking in a Forster and Smith catalog. They have a Orbit compact Fluorescent with Lunar lights (48" 4-96 watt,4 lunar lights) or HQI Halide/Fluorescent light fixture (2-150 watt HQI 2-40 watt T8 bulbs) Considering they are approximately about the same price ($500.00) Which one do u think would be a better light for a 90 gallon? << Both are a little low on light for a 90 gal.  But without doubt I would get the halide T8 combo over the four 96 watt fluorescents.  Hands down easy decision if you ask me. >> Thanks again for all your help! <<  Blundell  >> Photoperiod for lighting Dear WWM crew,   I have a 72G tank with three fish, some shrimp and snails and with some mushroom corals in QT. I run a custom SeaLife Orbit fixture with 2X96W daylight and 2X96W actinic bulbs. My goal to stick with mushrooms and mushrooms only -maybe some Ricordea. I have the actinic on for 13 hours a day and the daylights on for 12. Is that enough light if the lights are 4" from the water surface and the corals will be within 10" of the surface directly under the bulbs. << For things like mushrooms this is fine. >> Next, I've changed my lighting schedule from 7AM-8PM to 5AM-6PM. And as winter approaches will change to 3AM-4PM. The tank will not be in total darkness until I go to bed around 11PM. Will it be a problem if the lights go off at 6PM but some dim lights are on in the room until 11PM? << Not this is fine... may actually be good. >> I don't see this affecting anything but the fish... Thank You, Narayan <<  Blundell  >> PS- Am I right in assuming that the skimmer isn't producing because there is very little to remove. << Is usually the case. >>

Questions about lighting for new tank Hello <Hi Cliff, MacL here with you today.>  and thank you for maintaining such a informative site, already you have saved me from buying a Electric Flame Scallop that would have set me back 25 dollars and most certainly would have had me scratching my head as to it's untimely death. <The site continues to amaze me and I work here.>  The information here is invaluable to someone new like me to the hobby.  I have read quite a few posts about lighting on your site, and now have a few questions of my own.  I presently have a 29 gallon with 16 lbs live rock, 1 small yellow tang, 1 false Percula clown, and 1 neon goby.  There are also the following invertebrates: 1 cabbage coral (small) (green star polyps also share the rock this coral is on, though I am slightly concerned the star polyps have grown quite fast and the mat is now growing onto the base of the cabbage coral), 2 umbrella corals (small), 1 colony of brown Zoanthids, 2 pieces of Ricordea on small and one large, 2 metallic green knobby mushrooms (not sure of this though as I have not been able to find pictures of this mushroom on the Internet and all the books I found just lump all mushrooms together), and 4 other various mushrooms.  This is all lit by a SmartLite retrofit 65w power compact half actinic half daylight.  Ok I am setting up one of my 55 gallons for saltwater and plan on adding 30lbs of live rock to the 16 I have, since the 29 gallon was just to see if I would be able and want to do marine, plus the yellow tang will need more space. <Nice thinking.>  I already have one electronic VHO ballast that can power 2 tubes, which I hope to use in the tank.  The tank has a canopy which I do not want to give up as the tank sits in my living room and I desire a neat appearance.  So I plan on using two 46.5" 110w bulbs, one actinic and one daylight maybe?  I want to be able to keep more soft corals (the LPS types as I get more experience) and clams, maybe SPS but not likely as I have looked at them at the store and don't see much that I like (but in life many things start this way). <I really think to keep the clams you are going to need to go into the halides, sorry to say.> I want to add the Coralife 4X65W retrofit to the VHO lighting, is this going to be too much light for what I have now and will this be enough for my future aspirations? <Its not too much, it should keep what you have okay but you'll need to be careful if adding anything like LPS SPS or clams.>  In what combinations should I have the lights i.e. how many daylight, actinic, and which of them VHO and which of them PC. <That's a toughie because it really depends on the actual corals you want to keep AND it depends on the "look" you like for instance if you want your tank to have a "blue" cast etc.>  Also I would like to do three different light schedules since the setup will have 3 switches one for the VHO and one for each pair of PC, first set 12hrs next set 10 hours and final set 8 hours, is this a good idea or not necessary? <It will simulate daylight a little more naturally, you probably want your actinics on first.> Once again which bulbs and which colors in what order?  Another question should the tank have glass covers or not (kinda want them for evap and possible fish jumping out but not really a deal breaker)? <More light without them but for what you have fish and corals currently you should be fine.> Final question LED's for moon light heard that it is ok because they don't bother the livestock but still let me see what goes on at night, so could I add these for me? <I gotta say I LOVE the look of moonlights. so much so I'm trying to figure out how to get them on my tank.> Thanks for taking the time to read this lengthy email and taking the time to answer it, Clif  <Hope this helps Cliff, MacL>  

Which Light? hi guys! shifting from fresh to salt water was my plan. my current tank measured 72"Lx18"Dx19"H,to keep a few fish and if possible some corals maybe but don't have any idea about the latter. tons of research I have done so far but still so many questions here. I prefer fluorescent tubes for the lighting and to go beyond that would not be my option cause budget is the prime concerned so I omitted the MH's to my plan. I have two to choose form;1)50/50 full spectrum 6000K/actinic 36W 48"L 2)corallife full spectrum 20000K.which of these two do you think would fit for my tank? hoping for your generous help soon. THANKS! -Arnold >>>Hey Arnold, I'm a big fan of the 20K's, much better color rendition. However you didn't mention anything about the wattage of the 20K fixture. For fish it doesn't matter, but even for low light corals, and with such low wattages, (you mentioned 36W) you really should have the entire length of the tank lit. Even then, I don't really think 36w is going to cut it. I'd shoot for 96w fixtures - minimum, otherwise you'll just waste more money by upgrading later. This is one of the biggest "if I could do it over" issues you hear among reefers. Get the lights you really want the first time. Regards Jim<<< Natural sunlight tank I'm looking at building a coral tank in my office similar to my current freshwater tank that uses natural sunlight to light the tank as well as a full spectrum bulb to lessen shadows. << I like these tanks.  I've had a few of them that did great.  Biggest problem is algal growth and not enough sunlight hours in a day. >> These are the specs I'm looking at: 10-20 gallon acrylic bowfront 2+ inches of aragonite sand 10-20 lbs live rock Mushroom and other various soft corals No fish or inverts (coral only) << Well this is sounding good. >> The freshwater tank is a planted tank and I have no algae growth with the direct sunlight it receives.  I have a few hours of direct sunlight which make a stunning display and the plants seems to love the extra light.  The new tank will be directly next to a window on my desk.  It will receive both direct and ambient (but still strong) daylight all day long.  Also, the environment is rather cold (about 68F- 70F all the time.  I work in a datacenter that overlooks a large marina.)  To be more exact, the corals will receive about 4 hours of direct sunlight (through a thick, slightly blue tinted, projectile resistant glass window) and the rest of the time ambient sunlight until the sun goes down.  I was also thinking of adding a bulb or two just to accent the sunlight. << Not a bad idea.  Especially with a tank that small you can buy a little two bulb pc fixture for cheap and it will do well. >> The chance of extreme algae aside, what are the downsides to using natural sunlight to light a mini reef tank. << So much white light often washes out the blue look. >> Will I by any chance "sunburn" the corals with so little water? << No, in the wild they grow right out of the water. >> Will there be any problem of the sunlight coming in from the side as opposed to the top (light having to pass through a few inches of water as opposed to a few feet)? << No this is fine, and maybe even beneficial. >>   Should I not use soft corals but use something that requires more light (since I have it)? << I'd stick with low light corals, let them establish, then look to add something else. >> Thanks in advance, -Eric <<  Blundell  >>

Lights for a 90 gal Hi guys, I am on your site almost nightly learning. << Me too. >> I have recently  lost most of the corals and a handful of fish in my tank.  Before I try  again, I'm planning to upgrade a lot of things, lighting is one of them. << I'm really starting to think this is more important than I even thought before. >> Its a 90 gallon tank, and I currently have a 4 x 65 watt Coralife PC(2-10k, 2- actinic) and a 96 watt 50/50 Coralife PC. << Doesn't sound like much. >> I want to keep some SPS corals, several LPS corals, an anemone, and maybe some clams, etc. << You need more light. >> I am removing my glass top.  I know which system I want, I'm just torn between the halide wattages, I don't want cooked corals.   I'm ready to  buy a Hamilton 2 x MH(10K), with 2 X 110 VHO actinics. Am I better off with 2-  250 watt halides(10K) or 2-175 watts? << Oh at least the 250's.  I'd even consider 400's. >> I am moving my leftover 4 x 65 PC hood to my 55 gall freshwater tank, it needs light.  Would adding my leftover 96 watt 50/50 hood to either metal  halide system be overkill? << No not all.  But I don't think you need it.  I'd be tempted to add it though, because I love light. >> I only ask this direct question because your FAQs vary greatly in what's recommended for lighting.  I truly appreciate your advice. James <<  Blundell  >>

Lights for a 90 gal continued Thank you for your response,   I found a good deal on a PFO with 2 x 400w MH  13K and 2 - 96w  actinics.   Is the spectrum ok?? << Now we're talking'.  Sounds great. >> Since you love light so much, might  you be willing to pay my electric bill from 1000 watts of light- :). << You got it backward.  I love lights not bills.  I should ask you if you want to pay my bills.  Just kidding. >> Just  need to know if you recommend this PFO system- then again, anything beat my  current system, and having a flashlight over the tank would be more  effective! << Yeah this sounds good. >>   Should I keep my tank top open? Is hanging the said fixture about  12" above the tank right? << I like my bulbs around 3 inches from the water.  But you will have heat issues so fans and an open canopy are certainly recommended. >> I truly appreciate your advice, Blundell. << You bet, that's why I'm here. >> James Pruefer, Rhode Island <<  Blundell  >> Lighting Questions 9/15/04 Hi guys, Lighting question. I have a tank that measures 72 x 19 x 20.  It has a canopy, and I was considering using four 72" VHOs. There is room in the canopy to have two more 72" bulbs, but this would add considerable expense. Are the extra two bulbs worth the expense in your opinion? <yes... if you want better growth in reef invertebrates kept underneath> Also there is an 18" glass support in the middle of the tank. If I place the bulbs 2" from the surface, will the support hinder the light penetration? <an impediment yes> Will this light be sufficient for brightly colored SPS at the top and LPS at the bottom?   <top 8" for the former... yes> If I opt for the three 250 HQI pendants, will this be too much light for LPS on the bottom and brightly colored SPS at the top? <nope... not likely> Do the HQI really out-perform the standard moguls? <the tests seem to indicate this is so for many brands> By mounting the bulbs in the canopy, there will be a lot of light lost to the top of the canopy. How detrimental will this be? <no harm... just a waste of electricity> If I mount them to a board and put this board in the canopy, there will be no way for the fans to blow air across them.  I hope this all makes sense to someone other than myself.=) Thanks, Randy <best regards, Anthony> To Metal Halide or to PC? Greetings Crew! Just when I think I know enough about this hobby, I realize that I am still lost at times.  I need your help and guidance on this one as there is so much info in the archives (spent about 2 hours reading today).  Sorry for being a little long, just that there is a lot of info to cover. Recap of my system is a 55-gal minireef that has been up (post-cycling) for almost a year.  Water conditions pristine for months.  Even have a CPR hang-on refugium growing more algae (tang heaven) than my tang can eat! For the most part, everything is doing great (lost a shrimp, one fish and a handful of snails since starting).  I learned a lot of hard lessons (pre-WWM days) and had to replace several components bought cheaply for quality ones (e.g.:  SeaClone for Remora skimmer).  The last thing remaining is the PC light fixture bought cheap on EBay.  It is rather ugly, about 1/4" short to fit on my tank, and has no vent fans so during the summer, I need 2 fans blowing on it to keep the tank cool (ugly).  I am now in the EARLY planning stages of replacing the lighting. I currently have 2x65W of 10,000K and 2x65W 50/50.  The tank dimensions are 48x12x20.  The sand bed is about 17" from the surface.   Here are the light-requiring creatures (besides algae) and how far from the surface they are: Brown Zoanthid polyp colony, 14-17" Open brain coral:  17" (bottom) Orange polyp colony:  5-8" Yellow polyp colony:  9-12" Colt coral:  7"-17 (on bottom rock) Mushrooms:  8-13" green star polyp:  9-11 Rose anemone:  center @ 10" I know now that anemones and corals don't mix, but I have gotten lucky in that it has not moved since day 1 (going on 8 months now) and it has tripled in size (still not near anything else) and has beautiful rose color.  It is in the dead center of my tank (perfect spot) and I do not plan to add any other corals.  So, I am planning to keep it until I can afford a species-specific tank for it sometime in the next year or so. So, back to the lighting upgrade.  I have been considering switching from PC to MH.  I ran into someone in my LFS who was selling some equipment (heading to Iraq for 1 year) and he offered me his 48" light hood. It has 2x400W 10,000K MH and 2x96W VHO.  I almost bought it, but decided to research it first.  Glad I did.  If I got that, I would have to: A:  mount it four feet from surface or B:  Add Coppertone sun block to the water So, back to my original plan of building a hood.  Just still confused about how much lighting I would need and how to make the switch to avoid hurting my beautiful corals.  Don't worry, I will research plans well ahead of time and have an engineering degree to rely on. Plan 1:  2x175W 10,000K MH and 2x65W PC actinic Plan 2:  4x65W 10,000K PC and 2x65W PC actinic Plan 3:  Keep my same 2x65W 10,000K and 2x65W 50/50 I would like more blue in my tank so I am leaning towards #1 or #2.  Halides would be mounted ~8" above water surface. Now for direct questions: -Opinions about my plans? -Do you measure from MH bulb to water or reflector to water? -Is 175W MH appropriate for my system? -How do I switch from my current PC to MH without shocking (or sunburning) everything?  I've read several different ways and I am still confused. -My initial plans would have a cover, bulbs and reflectors weighing about 10-15 pounds, is this too much for my tank--bearing in mind I have a HOT skimmer, refugium and whisper filter on the back?  It would be distributed on the 3 sides that the HOT things are not on. -Should I place glass over the tank (with MH) to prevent splashes from hitting MH bulbs and/or reflectors?  Is there a better way? I have 2 potential jumpers so some covering is necessary. I know this has been long and there are lots of questions.  I apologize.  Take your time answering because I am in very EARLY planning stages and things won't solidify for several months (plan to be up-and-running by new-years). Thank you so very much for all your help the last 9 months.  Somehow I don't think I would have as wonderful and enjoyable of a tank if it was not for your wonderful site and dedicated experts helping marine newbies like me out. -Ray PS  My Percula that was sick is now her same old self and is now back in the main tank eating like there would be no food tomorrow! ****Hey Ray, At 55 gallons, you are safely out of the mini reef category, congrats! :) We usually only refer to tanks 30 gallons and under as "mini" reefs. The organisms you are currently keeping are not among the most light demanding of reef inhabitants. I'd say the E. quad (bubble tip) needs the most light, however even these are fairly forgiving. Out of your listed options, I would go with #2. You don't NEED anything more than a good PC fixture with your current stock list. However MH's can open up more options if implemented wisely. They look better too. :)   If it were me though, I'd go with a 2x150W double ended HQI metal halide setup. ( I didn't choose #1 on your list because I don't like the 175W 10k's.) Your current animals will still be happy, but you have the option to add some slightly more light demanding organisms if you wish.  Look at the Aqualine/AquaMedic fixtures. The bulbs? I would run 20k's. That way you can forget about actinic supplementation, and you color rendition will be fantastic. You can play with the height of the fixture until your critters are happy, and lower if needed. I just switched to 250W DE 20K's after running DE 10K's for two years, and I'm never going back to the 10k's. You can also run 150w, or 175 watt moguls, but I would stick with 20k bulbs. When I say "DE" above, this means DOUBLE ENDED, and they are brighter then the equivalent wattage in a "mogul" or standard screw in bulb. 150W HQIs are really the best bang for the buck when speaking of power consumption. Hang the fixture above your tank, do NOT use the tank to support it. There are a few reasons for this, but mainly you want the ability to adjust the height quickly and easily. Confused yet? :) 1.Bulb height is just what it sounds like, the distance from the bulb to the water. 2.175W mogul bulbs with actinics will work, but I would run 150W double ended bulbs, 20K, no actinics. 3.Raise the fixture a bit higher above the water initially, and lower as your critters adjust. 4.A fully covered tank will overheat running MH's. Try a 4" cover just around the perimeter of the tank. this should discourage any jumpers, but still allow heat to  escape. Bubble tips do just fine in many reef setups. I have 6 of them, along with various corals. Cheers Jim***

Lighting a 55 gal FOWLR Hi I have not written to you guys for about two years, since all my problems w/ my baby morays. Anyways I feel I have come a long way, and am past the point of no return :). Anyways, I'm nearing completion of my tank setup, and was really hoping you could give me your views on how it is going, and I also have a few specific questions as well. Well, here's the setup: 55 gallon tank, FOWLR, inhabitants are 1 medium purple mouth moray (Gymnothorax vicinus - what a pain it was identifying this guy! I know this cannot be his final tank, he will be moved in about a year's time to his final home which will be over double this size), 1 coral banded shrimp, 1 skunk cleaner shrimp ( they have homes on opposing sides of tank, and haven't killed each other yet), 1 starfish, maybe 15 snails.  1 hang on tank mechanical/biological filter, with some ceramic beads I'm slowly removing because they are a detritus factory, and the unit has 2 carbon holding sponges, of which I change one side every other week.  1 aqua C remora skimmer, with maxi 1200 upgrade, constantly cleaned 2 maxi jet 1200s on the ends of tank for circulation, thinking of throwing in a Rio I have sitting around, don't even know if it's necessary in the tank though. << You can't have too much flow. >> 1 pc lighting unit, w/ a 36 watt 50/50 bulb << That is very little light. >> also I'm very good about water changes / top offs etc.. okay, any criticisms / ideas would be greatly appreciated, now on to my questions. as far as biological filtration, I have a 1.5 '' aragonite bed ( probably doesn't' do much at all), and only about 20 lb of live rock. << I'd double that. >> here's question 1: instead of purchasing live rock, which turned out to be a disaster (I used to have more than 20lb, but any piece that wasn't large the eel would bang into the glass when he played w/ them), I decided to make 2 large structures w/ the Aragocrete method. the first, which should be done curing in about a month, is 30 lb, and is composed of 20 lb dry Tufa base rock and the rest an Aragocrete mixture. the second structure is 30 lb, but is a mixture of maybe 4 cement : 1 crushed oyster shells, and the exterior is totally covered in oyster shell. << I've heard, and personally seen, really bad results with oyster shell. I'd be hesitant to use it ever again. >> I know adding aragonite helps with porosity, but I painstakingly made this structure day by day for weeks, adding layer by layer of pebbles of cement/oyster shells, so I'm pretty sure water can get through the entire structure. << I just saw a fantastic presentation the other day on Aragocrete construction. This guy (who is amazing) said the key was to use as little water as possible when mixing up your cement. That was the key to increasing porosity. >> this is actually a multiple part question. will coralline develop quicker on concrete, especially if it is covered in oyster shell? << Hmmm, no. I'll say light is more important than the material. But darker colors help. >> can I count the second structure pound for pound in my LR: gallons ration if it is a very loose structure? << I don't like that measurement anyway. I'd say just fill your tank so there is plenty of rock. Whatever weight it is what it is. >> will 80 lb of rock in the tank be too much? << Impossible. Don't worry that won't happen. >> the second structure weighs 30lb, and only has 3 points of contact with the tank. << That is cool. >> my next question is about lighting. I had been told by some people that 1watt no= 1 watt pc, but in re reading all the lighting faq's I see you're saying 1 watt pc is 2-3 times brighter than 1 watt no. << Absolutely. >> all I plan on doing in my tank is keeping it looking nice aesthetically, keeping it feeling natural enough to the inhabitants, and making coralline grow like crazy. (side note - just turned around and saw cleaner shrimp - just got him yesterday - cleaning eel for first time!!!) like I said I have 1 36watt pc 50/50 over the tank. I also just ordered 4 moonlight led bulbs (matching the moon's spectrum). now, my plan was to purchase another lighting unit, and a new 50/50 bulb (mine's like 2 years old, making the Cyano come in!!), and then run a timer system like moon: dusk: day: dawn: moon, with the dawn/dusk being the new lighting fixture which would be 100% actinic, and daylight being the 50/50 plus the actinic, so during the day it would have a bluer effect. like I said I am concerned with coralline to grow as well as possible, and I want to have a blue effect even during the day. << This should be fine for what you're looking for. Still very little light, but that is what you want for coralline. >> what type / wattage lighting fixture would you suggest for the actinic one? << Well I'd probably run two VHO tubes, but if you already have one pc, then I'd just rig up another 55 watt pc. >> I was thinking of getting a NO fluorescent strip, which would be 40 watts, but actinic doesn't' look very bright, and the 36 I have is pc, so if I add 40watts actinic NO I feel like it won't seem that I've done very much. so maybe VHO 48''? << That would be great. >> I don't want to get a multiple bulb pc system, and the 1 bulb, I believe 96 watts, wouldn't really cover the length of the tank, and since my pc is only 24'', I want something that will provide better lighting. oh my bro goes to trade school and does carpentry/cabinet stuff, so he's coming down to my school in the next few days to get measurements, going to build me a custom hood, super deep so I can feed the eel by hand w/o worrying of him diving out of the tank (I feed him off a fork now w/ the tank cracked 1/4'', he's too crazy to open the top when he smells food! the hood will have a fan on both sides, creating a decent current over the lights, so I think they will be fine as far as heat goes, although I don't' have experience with this so I could be wrong.) Oh, if I wanted to add to the blue effect during the day, could I just leave the moonlights on always? << Yes, but they are very dim. I don't think you could see them during the day. >> if you would even be able to see them once the other lights are on *doubtful*. Well, sorry for such a long email. I've been shopping these questions around reef central and other places, but am getting mixed / insufficient responses. I just read through your LR lighting faq, and answered some of my q's, those faq pages are the greatest. thanks again, I think once I get these issues taken care of this tank should be quite nice, but I'll wait on your response before getting too comfortable << Good luck. >> << Blundell >>

Lights for a 20 gal Hello once again.  I've done some searching around on the net & on your site but I can't seem to find what I'm looking for.  I'm looking at buying the 24" Coralife Lunar Aqualight with 2x65w 10k & true Actinic, as well as 2 3/4w LEDs.  I can't find a review for them anywhere.  It's for a 20 gal tank and I'm not looking to be able to sustain anything, just some basic "beginner" corals. << I'd say this is fine light.  But for what you said, beginner corals, nothing fancy. >> Any bit of knowledge you have with this product would be greatly appreciated.  Thanks a bunch. << Sounds like the lights I had on my 30 gal at first, so you should be fine. >> Dean <<  Blundell  >> Lighting a 65 gal octagon tank Hi there. First of all you all do great work on this site. I've learned more here than you can imagine. << Good to hear. >> Now to the question.  Have a 65 gal Octagon tank (seems like this isn't too popular here) << Just difficult to light. >> with the integrated hood. Hood has (3) 15w tubes.  I currently have 1 actinic, 1 fluorescent (came with the system) and 1 zoo med coral sun lamp. I do have two coral life CF lights that lived on another tank.  The question is does all of my lighting have to come from above? << No, but most people don't like the looks of it otherwise.  It can alter coral growth, but isn't' bad. >> Since most of the hood is plastic, I can't place the CF in addition to the hood lights.  Is it feasible to light with the CF from the side near the top? << Yes, but you don't get nearly as much penetration if the light has to go through glass, and not just directly into the water. >> Making a mount for the coral life to hang on the side isn't too difficult.  This might seem odd but I'm looking to add anemone life here and want to make sure I have the light needed before animals die due to my stupidity.  Thanks for any advice. << Seriously, I would consider looking into a used 55 gal tank or something similar.  Rather than try to make things work with what you have, I'd just get a nice tank to begin with. Otherwise, your idea should work, it may look funny, but it should work. >> Jamie <<  Blundell  >>

Lights for a 29 gal Hi I am interested in starting a reef aquarium and am wondering about the lighting needed.  It is a 29 gallon 30 " x 12 x 18 high. << I have that tank. I currently have two 150 watt 20k halides. >> It currently has 25-30 lbs of live rock, a yellow tang, domino damsel, and a maroon clown.  << Wow sounds just like my tank.>>  I was looking at getting a power compact fixture that sits above a tank.  I am looking at a model that hold either one or two 65 watt bulbs. << Two is a minimum. >>  The single holds one 65 watt 10,000K /460 nanometer actinic and a 1 watt "Lunar Light".  The other one holds two power compact bulbs 65 watt a piece.  One is a 10,000/6700K and one is a 420/460 nanometer actinic with the same "lunar light.  The dual also comes with a switch to have dual control on the lights. << Much better, but still too little light for stony corals. >> If it helps the fixture is called a "Satellite Compact Fluorescent Fixture".  Would this be enough to sustain some "cool" coral life and allow it to grow well? << Yes, but with careful selection. >>  If so which ones.  Would it be more economical/better to get a normal plastic hood top that holds three 20-30 watt bulbs? << No, the compact system is much better. >> With the one that sits above the tank would I still need a cover? << No, but it is nice to clean a cover, and not have to clean the bulbs. >> If so I know it would have to be glass but wouldn't this reflect some/all of the light? << Yep, it is a trade off.  I'd probably not get a cover. >> Also what supplements and test kits would I need to sustain coral life successfully and possibly propagate the coral for friends, or even better profit? << None. >>  Also what foods would you suggest to feed coral? << Golden Pearls, Cyclop-eeze, and live phytoplankton. >>  Thank you so much for your patience, expertise, and an awesome website. Sincerely, Aaron.   <<  Blundell  >>

Supplements and lights for a new 29 gal I thought that you need to supplement reefs with calcium or strontium and make sure that calcium, nitrates etc, stay at a certain level.<< Well not nitrates!  You don't want any (or at least very little) of them.  As for calcium, strontium, magnesium... yes you do want them at a certain level.  That is tough.  If you don't have animals that utilize those elements, then you NEVER need to add them.  If you do have animals using those elements, then you do need to add them.  I add them by water changes, or liquid supplements.  But make sure you are testing their levels first, otherwise you don't know how much to add. >>  Metal halide lighting is a little expensive for me, how much did the fixture in your 29 gallon cost? << Okay, but don't tell my wife.  I think it was about $300 for the ballast, two bulbs, two brackets, home-made reflector. >> How often do you have to replace the bulbs? << Most people say like every 8 months, but I go at least 12. >> Also you said I couldn't  keep most hard corals, could I keep open brain coral? << Up high, yes.  Also, I'd directly feed it.  But that is still low light to me. >>  Also, what other corals can I keep with the power compact fixture I described? << Mushrooms, leathers, Cladiella, Zoanthids, star polyps. >> Lastly, how often should the bulbs be changed in a P/C Fixture? << Hmm, every 12 months?  Not sure on that.  I go a long time with mine (like 18 months). >> Thanks a lot Aaron <<  Blundell  >> Lights for a 60 gal hex Hey there guys, Quick question I looked and wasn't clear on the lighting requirements for my tank. I have a 60gal hex. << very difficult to light. >> I want to keep soft corals and inverts. As well as a few fish I currently have 2 cinn. clowns and 6 snails (different species). I got a great deal on a 175watt Hamilton MH fixture with a 14k Ushio bulb( $100.00) used. << That is a good deal, and a great fixture. >> Do I need to supplement this with another light? << Hmm, well it wouldn't hurt, as those tanks are deep.  But that is a good light for most corals. >> I will hang it and add a fan to keep my temp regulated. When applying the wattage vs. gallons do I take in to consideration the sand live rock etc... or just go by the tank size of 60 gal? << Most people just do a watt to empty tank gallon ratio.  But a better measurement is watts to tank depth.  In this case, you have a deep tank. >> Thank you Jeff <<  Blundell  >> Light schedule? Hello I just ordered form Marine depot a deluxe fixture with 2 175 watt MH and 2 40 watt actinic fluorescents for my 75 gal tank 18 to 20 inches deep,<< Sounds good. >> and upgraded the bulbs to 2 10K Ushios is this good? << Yep >> The hood came with its UV protector and fans. Basically just to plug and use. Its about 6 inches high should I raise it more? << Oh no, if anything I would lower it. >> I could with 4 inches or more pieces of wood on each side what do you recommend? My tank has a glass cover right now should I remove it or leave it so the fish wont come out what do you say? << Okay I like glass.  Not across the whole top, because I don't think you can keep your tank from over heating.  But I do like glass under bulbs because I think it is much easier to clean glass shields than glass bulbs.  Plus I like to have the glass just to be safe regarding the UV issues. >> And also how much long should I leave the lights on and off with the timers? << Well start at like 10 hours, and gradually increase the cycle to around... oh.... I'd say 14 hours. >> MH and fluorescents each have their power cord how do I do this the time periods? << Actinics for 14 hours, and halides for 12.  That varies, but that is what I like and recommend. >> and how do I do to simulate the dawn and dusk effect? should I quarantine an anemone << I don't think so.  I think that causes more stress, and I would just try to gently add them as carefully as possible. >> and if I do does the QT tank have to have intense lights for those 2 weeks they are Quarantined? and how much cooper should I add to my QT for my fishes?  << Whatever it says on the bottle. ???  But I don't know. >> thanks a lot <<  No worries, good luck.  Blundell >> Lighting for 100 gallon tank 19 Aug 2004 hello WWM crew... <Hi Ed, MacL here with you this afternoon and let me tell you I'm very sorry for not getting back sooner.> I wanted to get your opinion on lighting for a 100gal. marine aquarium, right now it's a FOWLR setup with sump and skimmer, powerheads. I want to upgrade the lighting to someday possibly do corrals. I'm thinking along the liens of 500 to 550 watt's, would t5 HO's or PC be the best, I don't have the bucks for MH, but I can dream, ha ha. <Personally I like pc's but I keep seeing better and better things out of the t5's and some of the VHO's are MAGNIFICENT!. Standard rule is to try to get 5 watts per gallon. I would think hard about what you want Ed then set your lights up to accommodate them. Good luck.> thanks ed