FAQs about Fluorescent Light and Lighting for Marine Systems 1 Related FAQs: Fluorescent Light 2, Fluorescent Light 3, Normal Output (NO), High Output (HO), Very High Output (VHO), Compact Fluorescents (CFs, PCs),  Compact Fluorescents 2,  T5, TN Fluorescent Lighting, & FAQs on Fluorescent: Fixture Selection, End Caps, Ballasts, Regular and High-Output Lamp Selection, PC Lamp Selection, T-5 Lamp Selection, Lamp Life-Span Issues, Power Consumption Issues, Installation-Wiring, Troubleshooting/Repairing, By Make/Model/Manufacturer: & Metal Halide Lighting, Lighting, Lighting Marine Invertebrates,  LR Lighting,  Tridacnid Lighting, Small System Lighting, Related Articles: Fluorescent Light, Spectral Quality of Various Fluorescent Lamps by Dana Riddle, Coral System Lighting,  NO fluorescents are fine for me... Antennarius pictus pic in N. Sulawesi by DianaF.

HelloLights and their prices - 11/23/04 Do you guys know of HelloLights to be a reputable dealer. <Absolutely!!! Why wouldn't they?> I certainly don't want to offend or suggest them of any wrong doing, but their prices on URI VHO's seem to good to be true. <Why is that? They are likely able to offer prices like that because they buy a large amount and get a better price break or maybe they have something worked out with URI. You never know. I gave them a call just to verify and their customer service agent was able to basically allude to the fact that they buy a huge amount directly from URI and get a better price due to volume. From the URI factory straight to the consumer.>  Are any of these possibly imperfect at $17.50 for 4 ft. 110 watters? <Nope, if you can use the T12 footprint, sounds like you found a bargain, and now thanks to you, anyone else who reads the FAQs today will also get to take advantage of the price as well. I did a little research myself, and from what I can see, everyone else is about 5-8 dollars more. Stock up, bubs!!!! Thank you Kevin! =) Thanks for participating here at Wetwebmedia.com ~Paul> Thanks  -  Kevin

T5 Lighting and Corals Hi, I have a question about light intensity of T5 HO lighting. I have 29 Gallon 18" deep tank with 4 24W T5HO bulbs with highly polished reflectors. Bulbs I have are 2 6000K sun, 1 Blue and 1 Actinic. How many watts per gallon is 96 watt of T5 equivalent to or 3.3 watt per gallon of T5 light equivalent to. Most of T5 HO lighting discussions that I've read say that T5 Lighting has more light intensity per watt then other fluorescent lighting and I like to know exactly how much more light is more. <Equivalent in terms of intensity... compared with VHO, HO fluorescents? PAR values? More by double...> Actually, I wanted to know if I can add corals with moderate lighting needs in my tank with my current lighting. Thanks you, Hans <Yes... even high light and quality stony corals will do well under your light regimen. Bob Fenner> PC's or T-5's Hello Crew, I have a 55 gal.  tank with a pair of  false Perculas, a pair of Firefish and some basic corals (mush, polyps leathers). The  tank is currently lit with 4 - 55 Watt PC's.  The lights will need replacing soon and I would like to get a bubble tip anemone for the clowns.  I do not want to get into MH's for various reasons and have seen conflicting info about the feasibility of keeping anemone's without them. Question is  as I need to replace the bulbs soon anyway (cost about 100$) would it be worthwhile to convert to T5 lighting? << Only if you can fit more bulbs in there.  Otherwise, I don't really see an advantage to this. >> Cost for retrofit kit w/ 4 54 watt bulbs is 329$ I looked for Q & A onT5's earlier and could not find anything.   << Well if not halides, you may consider VHO.  But since you already have ballasts and a fixture, I'd go with replacing the pc's. >> Thanks again - Kevin H. <<  Blundell  >> Lights for a FOWLR Hi Guys, First off, your website is awesome!!!  Most informative, especially for the novice marine aquarist, but sometimes since I'm a novice, it makes my decision making difficult, so I'm going to ask the pros.  Anyway, I've got a 46 gallon bow-front, that is 24" deep and 36" wide.  I am currently using the factory bulb issued with the aquarium hood.  I'm interested in getting a couple of pieces of live rock to provide some natural grazing ground for my Kole Tang and Yellow Tang.  I also have a couple of clowns and a Brazilian Gramma, and will eventually be adding some cleaner shrimp and hermit crabs, etc.  What are the lighting needs to just support live rock?  << Well basically none in terms of biological filtration.  But the more light (and I think the more blue light) you have the more you can grow.  So if it is for herbivory then I'd say as much light as you can get. >> I would like to continue to use my factory hood (which only supports one bulb), but which bulb should I be using?  I was looking at a Zoo Med Reef 50/50 Bulb, but it's only 25 watts.  Your advice is much appreciated. << Well that is a fine bulb, but I'd consider taking apart the light and gutting it out to hold either a VHO light or multiple pc lights.  If not, you are really limited on what the live rock will grow.  However, even without light, live rock is excellent to have. >> Once again, love your website!!! The Novice <<  Blundell  >>

Tar vs. Electronic ballasts Good day, Can you tell me the difference between a tar ballast and the other types of ballasts? << Sure, but in simple terms because I don't know much about them.  The other kind of ballast is an electronic ballast.  My understanding is that an electronic ballast will run all bulbs (of a certain wattage) but a tar (also called a coil) ballast will run some bulbs but not all.  However the main difference is that a tar ballast is way stinkin' hot and will burn you after has been on for a few hours.  An electronic ballast is so much better.  I have them, and can't imagine using any other type of ballast.  I only recommend electronic (although they are much more money like $150 USD as opposed to $50 USD).  If you want more in-depth info please write back. >> Which is better? <<  Blundell  >>

Reef Lighting  Aloha, <Greetings.> I have a 75 Gallon tank. I am not wanting to take a shortcut on lighting. I want to keep some SPS and clams. I keep my house cool (about 70 degrees) I will have 4 - 4" fans in my custom enclosed canopy over the tank (hanging pendant- style out of the question unfortunately). My canopy will be about 8 to 12 inches over the tank. I plan to purchase a sheet of polished aluminum and line the entire inside with it. <I'd get it at least coated with something... aluminum and saltwater don't mix well.> On to the lighting... I would like to retrofit 2 - 175watt 10,000K metal halides.  Complementing that, I can either buy an Icecap 430 and run 2 110watt actinics, OR I can purchase a 660 and run 2 110watt actinics PLUS 2 110watt 10,000K bulbs along with the halides. Is this overkill? <Hard to discern... you probably don't 'need' the extra 10K fluorescents.> Again, I would like a T. maxima or T. crocea in the near future. But I don't want to burn the SPS corals. <Make shady areas with the rock work OR drop one of the metal halides and light with the other on one side of the tank only, and then perhaps use the 10K VHOs on the side that doesn't have the MH lighting.> OK, if you're still with me, back to the MH. I have heard about UV rays, so I assume I will have to build some sort of UV lens for my MH. <That is correct.> Is this a special type of material or could I use a piece of acrylic? <I would use glass - acrylic will likely melt being that close to a lamp. Glass is available with a UV-filtering coating.> I could build a " box" over each bulb with it. Not sure if the bulb would melt it though. <It would.> I really don't want a piece of glass or acrylic over my entire water surface. I want evaporation for Kalk top-offs and cooling factor (with the fans blowing across the top of the water). <You might need to rethink this, with fans sucking hot air out of the canopy.> I am trying to come up with a plan to where I do not have to use a chiller, but get sufficient lighting. <I'd skip the canopy and instead light from above with adequate space for more fans. You will soon see that the canopy becomes a trap for heat, and you largest problem will be getting the heat out of the collector.> I have so many ideas in my head so if you could blindfold me, spin me around 15 times and point me in the right direction, that would be super cool groovyrific!! <Again... if SPS is part of your goals, then skip the second MH. Light that side with only fluorescents. You will still have issues with heat... you may need more fans or you may even need a chiller. Time will tell.>  Mahalo, Jason <Cheers, J -- >

VHO Lighting Systems for FO I recently purchased a tank used. It is in very good condition and has an almost new VHO lighting system on it. I was planning on making this tank a fish only tank with maybe some live rock. Is the VHO lighting system ok to use if it's not going to be a reef tank? It does come with a fan so I think the temperature will be controlled under the canopy. I was just wondering if it was bad for the fish to use two 110 watt bulbs. . . will it be too much for them? <No, it is not even close to how powerful the sun is in the tropics. It may fuel algae if you do not have your nutrient levels under control, but would be excellent for macro-algae growth and coralline.> Thanks for your help. . . hopefully my questions weren't too dumb! <No dumb questions here. Our purpose is to help and advise mostly new people. Do make use of the other resources on WWM; articles, FAQ files, etc. -Steven Pro>

VHO Lighting Systems for FO II Excuse the questions again, but what do you mean by "nutrient levels under control"? <Low levels of nitrate, phosphate, dissolved organics, etc.> If there is algae growth is that bad? <There are what are referred to as nuisance algae growths; Cyanobacteria, hair algae, dinoflagellates, etc.> Would my three tangs appreciate it? <Many of the nuisance algae seem to be unpalatable and go uneaten.> Would they take care of it? <It would depend on exactly what was grown.> How do you know the difference between good algae and bad? <Take a look here for the many writings on algae http://www.wetwebmedia.com/Marind4of6.htm> Would keeping the lights on 8 hours per day be a good time limit? <Better to control the nutrients.> Thanks. <Please read as much as possible of the various articles on marine aquariums and their care. -Steven Pro>

Lighting A quick couple of questions. I am purchasing some new URI VHO 36" 95W lighting for my 55gal fish/invert. This is a three bulb system. The question is which bulb combination do you suggest. The available bulbs are Actinic White 50/50, Actinic 03 and Aqua Sun. <I would use one of each. All are great lamps for a good company.> Also note that I may add a 4th in the future as my IceCap ballast can support this. These bulbs have an internal reflector, do you think I need to add a reflector? <Not absolutely necessary, but will increase the amount of light into the tank somewhat.> Thanks, Dennis Vigliotte <You are welcome. -Steven Pro>

Lighting WWM Crew, What comments do you have about Full Spectrum Solutions' full spectrum bulbs? Spectra 5900: CRI 93, 5900K, 2500-3100 lumens Maxum 5000: CRI 91, 5000K, 3600 lumens http://www.fullspectrumsolutions.com/Fluorescent.htm I know Bob loves the Vita-Lites and was curious as to whether or not anyone knows anything about these. Thanks again. ~Rob <Sorry, but I have never heard of them. URI is my brand/company of choice. -Steven Pro>

Fluorescent lighting question I tried to read the Fluorescent lighting FAQ section on your web site but it's not coming up. The PC FAQ is, just not the Fluorescent page. I've seen that in a few other areas but I'm remiss in mentioning them to you. The frames and banners all load, but the content does not. There are no error messages. <Some of the article pages are not complete and merely have a link with no content, but all of the FAQ pages should work. I looked at this page has a bad link. The FAQ for fluorescent lighting is here http://www.wetwebmedia.com/fluoltgfaqs.htm> At any rate the question I have is a pure DIY question. I'm building a new canopy for my 80 gallon long aquarium. The tank is currently dry but should be full of water in a few weeks. The tank is 6 feet long with one opaque divider in the middle. I intend to put a glass top on under the canopy. Now that you know my parameters I'm looking into just using a 4 bulb 40W electronic ballast from Home Depot to power 4 36" 36W lights. As I recall if the bulbs only need 36W there is no problem with using a 40W ballast. <Yes, most of these ballasts will run 40 or 30 watt lamps.> I intend to use two full spectrum and two actinic bulbs on a FOWLR tank. (Alternately I may add a second two bulb ballast and run the actinics in there for sunrise/sunset simulation on a different circuit.) All of that said do you see any potential problems with the setup? I can buy an Icecap setup for about $120 or I can build my setup for about $25. -David Rencher <Do be sure to use water resistant end caps, plastic junction boxes, and follow all applicable safety codes for electrical work. -Steven Pro>

VHO replacement question Hello Bob, <Anthony Calfo in your service> Long time no talk, how have you been?  <so busy that he has had to graciously solicit friends to help out with the uber-site that we all know and love as WWM <smile>> I am getting ready to order and replace my VHO bulbs on my reef. I have always been using URI VHO bulbs, 2 actinic white 50/50, and 1 super actinic blue.  <a most excellent combination...and I love the brand. Before my coral greenhouse, I had gone through tens of bulbs indoors and settled quite happily on the URI products (I especially love the blues)> Although I notice that there is one called an AquaSun daylight 10,000k also made by URI. Should I keep the combination I have been using for my 30 gallon mixed reef, (hard and soft corals, clams anemones and live rock) or change it up a bit?  <you definitely have the best combination for a mixed garden display...I would not recommend a change> Also 8-10 months still good on replacement time of bulbs? <exactly for VHO lamps> As in the past, I really respect and appreciate any and all advice you share with me. <Bob is truly a great guy and one heck of a team player... he is a jewel in the aquarium industry. With kind regards, Anthony Calfo> Take care, Rob

Lighting Hello Bob, Tony, Steve My question concerns lighting for my 180 reef tank. Currently I'm using 2 VHO 160 watt actinics plus 2 VHO 50-50 bulbs to light the tank. What I'm wondering is if there is a combination of bulbs that would give me a deeper blue hue to the tank? I know that they make 1000k and 2000k bulbs in VHO now, and wonder if they wouldn't be better than the 50-50's? Probably the highest light demanding animal in my tank is either xenia sp. or a Squamosa clam. I get really great coral growth now, but would like a deeper blue look to the tank. As always your help is greatly appreciated. <The easiest thing to do is change to three actinic and one full spectrum if that is your desired look. One word of caution, what you desire to see may not be the best lighting for your animal. Also, I will give you a tip. I love URI lamps and in particular the combination of two actinics, one white actinic, and one AquaSun (full spectrum) lamp. This has a nice blue tint and has also demonstrated healthy growth.> Be talking, Joe G <Talk to you later. -Steven Pro>

55g NO lighting q's once again :) Hello Bob, or if you are not back yet, whomever is answering this. I think I will go with the four NO bulbs on this tank. 4 x 40w, 3 9325k and 1 actinic. Mr. Fenner, could you give me a link to Steve pro's NO 55g? OR if this is Steve, could you give me that link again? I would like to have another look at the tank to get some ideas. Thanks. <I am going to give you the link to the first page as the webmaster was going to be moving a few things around http://www.masm.org/ I have been successful keeping a variety of LPS, soft corals, mushrooms, and Zoanthids under NO, but I have been careful to avoid high light animals like SPS. A good book, like either of Eric Bornemann's or Anthony Calfo's, would be extremely helpful. -Steven Pro>

Lighting Question Hi Bob or Anthony, <tweedle-dum here...> Another quick question: (I got such great advice the first time I figured I'd pester you folks again). <we make half of the stuff up, but it's convincing> If I was going to upgrade from standard fluorescents to HO or VHO bulbs <no HO...a dying technology. VHO or Power compacts please> would it be possible to get a strip light fixture from a place like the Home Depot to operate them in? <a reflector yes, but nothing else. Need specialized end caps and ballast> And would I still need to invest in a good ballast too? <yes... and Icecaps have good customer service> I figure the brighter light would not only be great for the fishes but also for casting some cheer during the gray winter (Feb.'s the worst on the east coast). Thanks guys. "Warm" regards, Adam <alas, an expensive but worthwhile investment. Cheers from "sunny" Pittsburgh PA. Anthony>

Fluorescent Lites Robert and colleagues, What is your opinion of the Ott full spectrum fluorescent bulb. It is 5000K and a CRI of 96. Any good for marine applications (zooxanthellae, etc.)? <Don't have personal experience with these folks lighting (their lamps are very likely OEM'ed), but the values stated for temperature and CRI are very good... and full spectrum... likely of good aquarium use. Please read over the articles on light, lighting and related FAQs files for the type of application (freshwater, marine...) posted on WetWebMedia.com  Bob Fenner> Dave B

Lighting a 50 Gallon Hi Bob-   My father & I have just set up a 50 gal tank in his home office (Boy, is his productivity going to drop!).  The dimensions are 36"w x 18"d x 18"h.  He has purchased two single fluorescent fixtures (made by AGA - incl. a NO 30w 9300deg.K bulb each).  There is nothing in the tank yet except salt water, soon to be LR as well.   My question has to do with lighting the live rock.  My feeling is that this one-watt-per-gallon might not be enough to keep the LR healthy (?).  He could add a 2x96w CF fixture (he had planned to do this eventually...is now the time?) which then, added to the pair he has now, would net 5w/gal. Does he need to do this soon, or can he wait until he wants higher-Lux needing inhabitants?  In other words, will the LR benefit greatly from higher intensity lighting? <Yes, your growths of coralline algae and any macroalgae with definitely benefit by the increase in lighting.  But, if you really want to see the live part of you liverock take off, hold off on putting fish in for a couple of months.  I know it will probably kill you to wait, but you will see worms, copepods, amphipods, and a myriad of other life forms populating your tank.  This allows these small creature's populations to get a jump start before the predators (fish) are added.> With this additional fixture, what is your opinion as to the ideal color combinations of these bulbs?  My thought is to replace the two NO 9300K's w/ actinics, and use daylight spectrums in the CF's.  Will 60w of NO actinic be sufficient for this tank?  Or would you include a 50/50 CF as well? <I agree with your initial idea, two 30 watt Actinic 03 normal output lamps and two 55 watt full spectrum compact fluorescent lamps.> Thank you very much!  Erik Nelson <You are welcome.  -Steven Pro>

Going From NO to VHO Hello Steven, or Anthony??? I would like to ask you a lighting question today. Brief tank setup is as follows. 5'L x 30"H x 16"W. The tank is a see through from both sides, and overflow is on 1 end ( not in a corner). My rock is setup in a 2 level formation, and runs the whole length. I did this so I have more play with positions for my corals. I keep mainly soft, and LPS corals. I like that blowing in the wind look.. heh, heh. The lights are about 28" from the sandbed, and between 15", and 18" from the upper level of rockwork ( depending where you measure from, it varies). I currently have a Icecap 660 running 2 actinics, and 2 white fluorescents all from Coralife. They are presently NO lights. ( I am pretty sure this is not enough. I would like to go to VHOs. My question is this. I currently have all 4' long lamps that don't light about 6" on either end, and I want to change them to 5'. Will it be o.k. if the light will also shine directly down my overflow ( I have a standpipe in it that silences the noise), I am thinking if algae starts to grow down the overflow, it will make kind of a refugium ( I already have a refugium with Miracle Mud, LR, and Caulerpa as my filter system in my basement). Will going from 4' to 5' lamps increase the intensity also, even if I did put back the same types of lights, only longer ones. The fact that I want to upgrade to VHOs will increase the intensity already, and what concerns me is I cannot just turn them all on at once since the corals, and fish are currently not used to this brightness ( they are not even used to VHOs!!) Yet I have to move the end caps to add the longer ones. If I change all 4 NOs for 4 VHOs at the same time, but only turn on 1 of each at first for a week, or 2, should this be o.k. Or what is your opinion of how to go about the change, keeping in mind that the distance for all 4 end caps have to be adjusted at the same time. Also what do you think of the URI brand, or do you know of another brand that makes 5' long fluorescents? I do not want MH, as I think I don't need it, and the electricity, and heat problems! <Do change your lamps to four 4' or 5' VHO's. For the first week, run only two of the VHO's for your normal photoperiod and the other two for two hours in the middle of the day. Gradually increase the other two lamps two hours per week until they match your regular photoperiod. URI makes great lamps, my personal favorite. I would recommend two actinic 03's, one white actinic (50/50), and one AquaSun. -Steven Pro> Thank a bunch in advance, Greg N.( Montreal, Canada)

Scottish marine tank Hello Robert, I have had a Copperband butterfly for 4 months, are these easy fish to keep long term. <Mmm, most die within a week of capture. Ones that live a month or more can/do sometimes live for years...> Mine is feeding great and getting larger. The tank also houses 2 damsels 1 coral beauty 1 watchman goby 1 pajama cardinal. The tank is 50 gallon with 17 various soft corals, mushroom corals, tube anemones. I am thinking about getting metal halide lamps, for optimum coral growth, and hopefully get rid of hair algae. The tubes I have at present are 2 lifeglo,s 1 triton 1 marine Glo 1 marine white. I have had the tank running 1year , all occupants came out of a similar tank I had running for 3 years ,same type of lights etc . <Mmm, do take care in "grading in" the new lighting...> the filtration is external, with 1 internal with carbon and 3 powerheads for water movement. 1 external protein skimmer. tank conditions are 0 nitrate 0 phosphates 8.4 ph 1. 22 SG temp 82.but I still have to manually remove the algae every couple of days as well as cleaning the glass front, is it the tubes I have they are on for 11 hours.  <Seems like a "small price" to pay for such overall success> the corals are all doing fine with the exception of one or two, witch I feel don't open as good as they should, but are still okay bearing in mind they are all over 3 years of age. Should I replace my tubes with different tubes, or go for the metal halide. any help would be much appreciated, <I would switch your lighting on a regular schedule, replacing the "white lights" the Triton product and an actinic... If I were to invest money in new fixturing I would upgrade to compact fluorescents of about the same mix of white/03. Bob Fenner>

Lighting question for 55g reef Hello Bob. I have a question about lighting for a reef. I plan to get four NO bulbs for my 55g, and other than the lighting, the tank is reef ready. My question is, should I go with the normal 2 10,000k and 2 actinics, or a different combo? <I would use three of the 10K lamps and just one actinic... more of the wavelength, photons you want> I was thinking maybe the two actinics, and two sunshine bulbs, from GE that are 5000k 90cri. Would this make the tank look ugly and too yellow? What do you recommend? <These should be fine... for all but high-intensity light organisms (like tridacnid clams, many SPS corals)... otherwise, I'd be saving up for compact fluorescents. Be chatting. Bob Fenner>

Re: lighting question for 55g reef Thanks Bob. One more thing. What company would you recommend for the bulbs, like Coralife, zoomed, Hagen, or INTERPET? <Any of these company's lamps are fine (none of them actually make them)> Also, if I did the two actinics and two 5000k's, would the tank look yellow? <Not "that yellow" to me, but would look for 6,700K temperature or higher. Bob Fenner>

Shop Lights?| Have a question about lighting. I want to add more light to a 100 gallon tank. I'm thinking about using a shop light that you would get at the hardware store. I have a large oak canopy that covers the tank so the lights are not visible. I want the light for fish only and some live rock do you see any problems with going this route. <nothing dreadful, although the fixture is not designed or warranted for applications near water. Although many folks safely use them, they can be a bit of a hazard. Rather than buy three new fixtures in two years because they keep rusting out or shocking you... take a little time to look for a good price on a proper normal output (SO) fixture new, or even search locally for a used one in the paper or the LFS. Did you look online at some of the vendors in the links and beyond?> Thank You, John <regards, Anthony>

SO Bulb Color Dear Robert, <Sorry, but you got Steven Pro. Bob is out of town for a while and he asked Anthony Calfo and I to fill in for the weekend.> Can you tell me if the G.E. Aqua Rays Aquarium Tube that comes with the Oceanic Systems Nature View Deluxe Strip Light is a full spectrum bulb? I have checked with That Fish Place and others, but have not been able to get a definitive answer. Hopefully you have the resources to find the answer. <I have used the GE bulbs. They are good for a fish only tank, but I would not recommend them for photosynthetic plants and animals.> Thank you for your time, Mike  

Re: questions (on marine lighting... seemingly infinite choices on under-illumination) Hi Bob ! Yes........I have read though the WWM website regarding lighting.........but I still can't find the answers that I want. So.....here comes the questions again. Can I use 2 sets of retrofit fixture for my 24 inch deep 75 gallon tank? (one set consists of 2 X 37W 10,000K Daylight power compact + 2 X 37W Actinic Blue) Will it cause my corals to "burn out" ? Kindly advise? Thank you. <You can... but the system will be vastly under-illuminated... this is not enough watts of compact fluorescent lighting for this size/depth of system... this IS covered on the WWM site... Bob Fenner> Re: questions (ongoing... re marine lighting) Hi Bob ! Thanks for the reply. Sorry to bother you again. As mentioned by you earlier that the wattages are too low, how about increasing the wattages to the following combinations : 2 X 37 Watt 10,000K Daylight for the power compact + 2 X 37 Watt Actinic Blue + 1 X 25W 9,000K Daylight fluorescent + 1 X 25W Actinic Blue ? Lastly, how should the placement of 4 X power compact and 2 X fluorescent be?  Can it be (starting from the top to the front viewing portion) 1 X Daylight fluorescent + 1 X Actinic Blue fluorescent + 2 X power compact Daylight (placed in a straight line) + 2 X power compact Actinic Blue (in a straight line also) ? <Mmm, yes... But... have you read through the WWM site re marine lighting? I would install larger CF lighting altogether... for a 75 gallon system. Bob Fenner>

(Marine Lighting Fixturization) questions Hi Bob, <<JasonC here, filling in for Bob while he is away diving.>> I need your advice on power compact lighting. I intend to replace all 4 of my fluorescent tube lighting (2 Daylight and 2 Actinic Blue) that sit on top of my 75 gallon tank (contain fishes and corals) to a retrofit fixture which contains four power compact. My question is how many Actinic Blue and Daylight should I go for the retrofit fixture? Can the combination be four power compact Daylight (each is 36W 10000K) and use back the 2 Actinic Blue fluorescent? Kindly advice. Thanks. <<Best when using any type of fluorescent lamp to mix them 50/50, actinic and daylight. You can read up some more at: http://www.wetwebmedia.com/lighting1MAR.htm  Cheers, J -- >> Re: questions Hi Bob, <<Hello, JasonC here filling while Bob returns from his diving trip.>> I need your advice on power compact lighting. <<Ok>> I intend to replace all 4 of my fluorescent tube lighting (2 Daylight and 2 Actinic Blue) that sit on top of my 75 gallon tank (contain fishes and corals) to a retrofit fixture which contains four power compact. My question is how many Actinic Blue and Daylight should I go for the retrofit fixture? Can the combination be four power compact Daylight (each is 36W 10000K) and use back the 2 Actinic Blue fluorescent? Kindly advice. Thanks. <<Best when using any type of fluorescent bulbs to mix the bulbs 50/50 with actinic and daylight lamps. For you - three of each, daylight and actinic. Cheers, J -- >> Re: questions <<JasonC here...>> Thanks for the reply. <<my pleasure.>> Forgive me for not understanding your reply. <<Please forgive me for not explaining well, I will try again...>> Can the combination be four power compact Daylight (each is 36W 10000K) and use back the 2 Actinic Blue fluorescent? <<No, you want three of each, (3) daylight and (3) actinic.>> Will it "burn out" the corals? <<no, not the issue here.>> Mine is a 75 gallon tank and the dimensions are 2 feet X 2 feet X 2 feet. <<Should be fine.>> Kindly advice. <<Thank you.>> Thanks. <<You are welcome. Cheers, J -- >> Re: questions (Marine Lighting Fixturization) Thanks for the reply, Jason. Due to wrong information given to me by the retailer, I need to re-ask the following question. My apology to you. Are 2 power compact Daylight (2 X 27W 10,000k) + 2 power compact Blue Actinic (2 X 27w) + 1 fluorescent Daylight (25W 9,000K) and 1 fluorescent Blue actinic (25W) enough for my 75 gallon reef tank? (24 inch deep) <Mmm, not in my opinion. The types of lamps, temperatures are fine, but the wattages too low for such a depth system for many types of life commonly kept by aquarists. Please read through the Marine Lighting, Fixtures sections: http://www.wetwebmedia.com/lighting. tm http://www.wetwebmedia.com/lighting1MAR.htm and many associated FAQs for background, direction here. Bob Fenner>

Best Mix for Daylight/Actinic Fluorescents Bob, <<Not Bob, but JasonC filling while Bob is away diving.>> Enjoy your site, book and everything that you do. You been a great reference source for me. Without getting to gushy, I have a couple questions on lighting reef tanks. <<He will be happy to read/hear this...>> First, I have a 125 gal reef tank loaded with corals both hard and soft with 384 watt power compact lights two 96 watt daylight and two 96 watt actinic. Would it be beneficial or create more light to run the two daylight bulbs and two 50/50 daylight/actinic bulbs instead of my current setup. Just want to maximize the brightness for the corals to help them thrive. Would that make any difference at all? <<No, best with fluorescents to go half and half actinic/daylight.>> Similar setup in my 40 gallon tank. I have 4 32 watts bulbs split between daylight and actinic. Would 3 daylight and 1 actinic help anything? <<same as before.>> Or don't mess with it. <<I guess that's a yes.>> Lastly, I'm considering setting up a small 20 gallon hex tank for Sea Horses. What kind of lighting requirements would they need if I stayed away from most corals except maybe low light varieties like mushrooms? <<Not much, you could get away with perhaps small dual 9 watt PC tubes, same deal 50/50 actinic/daylight.>> I appreciate your help. <<No problem.>> Dan Hutchings <<Cheers, J -- >>

Buffering/lighting Hi Bob, My tap water does not have a lot of buffering capability. <Do you need, want more? Can be augmented easily> When I do my regular water changes (7 to 10days), the tank water has a pH of 7.8. I use Instant Ocean Salt and my replacement water has a pH around 8.2. I believe that the shift in pH after water changes is stressing my system.  <Good point.> I have started to use Kent Marine's Super Buffer and now my pH stays at 8.3 and. Alk = 4 mEq/l. Is this method of keeping up Alk/pH up a good idea or would the two part supplements be a better choice? <Two part would be better.> I did read the article in FAMA as requested by you about the Ice Cap ballast running NO fluorescence. I remembered reading that article years ago and another (same concept) with a plant tank. It really sounds like they are having tremendous results with NO tubes and VHO ballast. My main question here is with tube replacement. Ice Cap says 6x longer life. The recent article in FAMA state that regular replacement of the tubes have been unnecessary. Also in FAMA with the other article on the plant tank he state that he has been running the same tubes for years. Now what puzzles me is that this is exactly opposite of what most say. Hmmm? <The use of electronic ballasts in these cases does extend effective lamp life as far as I'm aware, but don't know about six times, definitely not indefinitely. You can test for intensity, spectral make-up over time... or just observe your plant livestock for changes. Bob  Brad

Vitalites, Dura Corp.  >They're Back!< I have been looking long and hard for the Vita-Lite locally. I called the 800 number and left a message. No response yet. <The manufacturer (Dura of NJ) is no more... you might find some old stock about though> What I finally found from a local lighting shop is the General Electric Chromoline 50 .... F30 T12 C50RS  I read over all of the lighting information you have on the web site and you do list this as an OK light source.  <Great product> I hope that my reading comprehension is working for me. My tank is 65 gallons and slightly tall. I have room for 4 of these in a 36 inch length. Should I add a blue light as well? What brand/type should I pursue. <I would make one of the four an actinic 003 lamp> Someone bought the monstrous sea slug at the local store. I noticed when I went in to look at lighting.  <Mmm, it might have perished> No one there can really help me, they know as much as I do...nil to nada. For all your help if you ever get to Southwest Missouri I will have to feed you (own a restaurant). Thanks Bob, Trisha <Yum. Bob Fenner>

Lighting Question Hmmm, "Dimmer Timer" do these exist for fluorescents? Any advice of where to look for these? If not, I will go with plan B and utilize the small 20W "NO" light. <At least for some types of fixtures/electronic ballasts... Am sending your note to the fine folks at Champion Lighting: http://www.championlighting.com/ for input/help> I also think that these new lights are raising the temp in my tank. I checked last night and the tank was around 84 degrees, it normally stays around 80 degrees and the tank is located in the bottom floor of my home (sort of a half basement). My guess is that a small fan under the strips would help push the hot air through the vent holes on the top of the strip lights. <Yes, one of a few countervailing strategies... best not to have such high temperatures, or diurnal fluctuations. I think my game of 20 questions "may" be over ;-) <I'd bet most anything our game is just begun here. Bob Fenner> Chris

Lighting dear rob, I have another question. I have just read your lighting articles and so I checked the lighting on my eclipse1 FOWLR tank and it only has one florescent tube. good thing I read the articles because I would have never worried about it. I am wondering if I could just order the twin lamp base assembly or is there another way to provide more lighting? <There are retrofit kits sold (compact fluorescent) that will fit this hood. Contact the various manufacturers, resellers (a bunch are listed on the WWM Links Pages) and state what you have. They will tell you what your options are... or go to the fine folks on our Chatforum: http://talk.wetwebfotos.com/ and ask them what they use. I would definitely add more light. Bob Fenner> thanks, dear rob thanks for the quick reply I didn't think I would get one so soon. you have the most informative site. ill be asking more about the sump design once I know what I want. since I found this site I don't even ask questions at the LFS because it seems like they are just trying to make a sale. <Ah, glad to be of help, but do always gather information, insight from other, diverse sources. Understanding baseline motivations in this world is highly desirable... but data is more so. Bob Fenner>

Lighting Question Hi Bob: Hope all is well. I recently had one of my ballasts go out in my Oceanic strip lights (2 30" fluorescent, using 2 'NO' 24" bulbs each). I was thinking of buying the oceanic replacement that uses the HO single bulb compact lighting. I currently have a fish only tank with about 5-6 2-4 lbs pieces of live rock. The question is do I spend double the money for these new lights (around $140 for both) or do I go the cheap way and just replace the with regular dual 'NO' fluorescent lights (probably $60-80)? Is it worth the upgrade? (e.g. brighter, better for the live rock etc...) <A good question... comes down to a consideration of really cost now vs. costs in the longer run and function/looks... The better lighting is better... and seemingly more costly... but will save you money in not so much time... in real electrical costs (versus useful light production) and replacement lamps/fixtures... Looks-wise and function wise the upgrade is definitely worth the small initial investment difference... I would upgrade> As always thanks for your advice. Chris Goldenstein <Be chatting my friend. Bob Fenner>

ZooMed (Fluorescent lamps) Hi Bob I love fluorescent technology as do you and think it to be the best, least costly way to light up our pets. <It is, to date, for "shallow" (let's say two feet of water or less) systems> I just popped on the ZooMed web site and I saw their Trichromatic Ultra Sun tube has a CRI rating of 98. Now that is incredible. (if true) Their 50/50 tube has almost the same spectral characteristics but adds the actinic. They also have a Coral Sun tube (actinic only) Have you had or hears anything about these new products? <Only from pet-fish sources in the industry and hobby... not personally and not "scientific" (like Dana Riddle's analyses). Consensus seems to be that they're "the real thing"> They are T8 size. From everything I have read, the T8 give off slightly more lumens per watt due to their narrow size. True? <Not size per se, but technological differences with other fluorescent formats> I think it would be great if this product is as good as advertised. One could easily fit 5 or 6 tubes over a standard 12 to 13 inch tank and raise many soft corals and some LPS's. <Yes, should be able to. Bob Fenner> Zimmy

Smartlight Hi Mr. Fenner, I've got to say that I absolutely love your book, CMA. Whenever I have a question or doubt, I go straight for my copy of that. It hasn't failed me yet! Thanks! <You're welcome my friend... do wish the eleven hundred page (w/o pix!) version would have made it into print... well, other works in process...> I have a question about my smartlamp setup. I've had some trouble with the system- the glass bulbs actually became detached from their white plugs (the part that plugs into the black socket... I realize I must have the terminology completely wrong, and can only hope you know what I mean...). I've spoke with the folks at FFExpress and they assure me they haven't had any trouble with this hot-seller. But it's happened to two of my bulbs. I sent the entire thing back for replacement, and I now have my new hood. <Ah, good... do contact Dennis at Custom Sea Life (the manufacturer) in town (San Diego) directly if there are further problems. Their link is on our website: www.WetWebMedia.com> I'm a little nervous about having a repeat of this. Is this because I put the unit right on top of my tank, with nothing between it and the water? <No, this should be okay> Is it possible that my powerheads are vibrating the tank enough to have caused this? <Hmm, maybe, but I doubt it> I can't buy that- to vibrate the glass so much that the hood shakes enough to destroy two bulbs, I'd think the tank's glass would have given out by now (knocks on wood). <Yikes> Can you think of anything that would have caused this? Have you ever heard of this before? Or am I just having some very strange luck? <Sounds like a manufacture, material defect... hopefully only one of a few... Bob Fenner> ~John

Standard Fluorescent lights Hi Bob. I have been reading on the GARF web site about the bullet proof reef system. <What makes these "bullet proof"?> There are many links on there that show absolutely beautiful reefs grown with standard fluorescent tubes. They even show gorgeous 55ga. tanks ran on as little as three tubes. Highly recommended are the Triton and Blue Moon tubes. 2 Tritons to 1 Blue Moon. As the tanks mature they add one or two more tubes. <Yes, all possible> How plausible is this? Does it really work? One lady has over 40 tanks running by this method that she used to propagate corals for sales. It would sure be nice if it were true and it really prospers as they say on GARF. <Matching other factors and taking more time are all part of these formulae> Another topic on S.O. tubes. A few years ago in FAMA a gent hooked up S.O tubes to Ice Cap ballast and had a much higher output coming from them. <Yes> If I remember correctly, almost as high as the VHO tubes. <Not of PAR> He was blown away by the results. Do you remember reading that? Did he ever do a follow up report and put it in FAMA? <Why not investigate on your own?> Your thoughts on this Mr. (World Traveler) Fenner. Zimmy <Start saving and come out with us. Plenty of room. Bob Fenner>

VHO compared with CF lighting hey Bob. I have a few questions...I have a 55 gallon reef tank (standard size 55 gal.) right now, I have 2 - 55 watt power compacts on the right side of the tank and 2 - 35 watt power compacts on the left...is this sufficient lighting??? <For? What sorts of organisms, desired results?> ..it is a homemade hanging hood, so I was considering putting all of the power compacts on one side and getting one metal halide for the other, does this sound better?? <Perhaps, with the MH lighting over more light-needy/using life> ... also, I have a Acropora coral that completed lost, or should I say, shed its color of green and is now completed white...did it die??, <Possibly. Or has just lost all its zooxanthellae... should have algae growing over its skeleton if gone> why would this happen??? <A few possibilities... could be the lack of adequate lighting, lack of biomineral, lack of alkalinity, infectious or parasitic disease...> will this process have any effect on the other corals??? <Depends on the cause/s> I have a calcium reactor and add strontium and iodine on a weekly basis, I do weekly 5 gallon water changes (with ro/di water), all other parameters are fine...thanks, Jeff <Time to re-read (leisurely) through your reef aquarium reference books, the gamut of material on marine set-up and maintenance posted on our site: www.WetWebMedia.com in search for "things that click" here. Bob Fenner>

Marine aquarium lights Hi Bob, I have a tall 27inches high 60 gal octagonal tank with three 15 watts fluorescent lights, one full spectrum, one Actinic and one 50/50. There is no room for more lights so I hope this is enough. Is this the right choice or should I have 2 full spectrum and one Actinic instead? I have a few fishes and I would like to get a few anemones if it is possible. <No to the anemones (if the popular photosynthetic types... you don't have near enough light). And the lighting you have is fine for fishes... if you wanted high-light need livestock, you might consider a single 175 watt pendant type metal halide... but I wouldn't do this in such a shaped system... very hard to control heat-wise> Also there is a glass between the lights and the water I know you suggest removing it but doesn't it protect the lights from corrosion? <Yes. Many folks use water-proof end caps over their lamps in such settings> or maybe it helps keeping the heat from the lights away from water, it's hard enough keeping the water temperature constant I'm worried that if I remove it the temperature changes will be greater when the lights are on then off. thanks so much for your help. Marc <Methinks you're ready for a larger system my friend... Bob Fenner>

Re: marine aquarium lights Thanks Rob, so you would say even with my system it's much better to remove the glass between the lights and water? <Yes, almost always the case> as far as heat from the lights you mean it makes no difference with our without the glass? <Makes some... actually in the vast majority of circumstances, this improves overheating... from evaporation> you seem to think that octagonal shaped system is difficult, why? -Marc <The "foot stamp" or surface area versus volume relationship... relative to more "stock" rectangular shaped systems... harder to aquascape, keep filtered, gaseous distribution hindered... Bob Fenner>

Lighting Hello Bob! I hope you are enjoying Hawaii Mr. Laptop, sand and surf. I do not know if you are aware of this or not but Dura is out of business. No more Vitalites. <Yes, I do know, thanks... it's a shame... their gear supposedly is still sitting in their closed factories in NJ...><<Actually, they're baaaaack!!>> On to my questions. I am going to make my 55 into a full blown reef tank. I am going to get 4-65watt PC's in a custom hood with fan. My concern is that from all I have read on these type lights are that none really are true full spectrum lights. <This is so... but with use of some actinic, not much of a problem> I have looked at the spectral curves from most every manufacturer of these lamps and all seem completely deficient in the red spectrum or just a smidgen at best. Don't many species of corals need some red spectrum to thrive? <Hmm, not really... what is considered "red" gets filtered out very quickly (almost all gone in top four inches of water)> If there are some could you give us salties out here a heads up? You recommend putting the lights as close to the surface as possible with nothing in between the water and the lights. How do you keep those occasional jumpers (fish) in the tank? <Ideally a lip arrangement of some sort... a surrounding mini-wall of glass or acrylic... over and around any openings> I want some Actinic lighting in the tank to give off that pretty blue coloration and the glow that some corals and fish give off but I don't want it too blue if you know what I mean. I was thinking two smart lamps and two 6700K daylight types. I have never seen these lights burn in person so I am unsure of the look. <They're very nice> I will keep mostly species of coral that are hardy and fairly easily propagated. I will sell off extra's to a LFS dealer in town and some friends upon occasion and share my experiences with them. Soft corals Large polyp stony etc.. Will this light be sufficient? <Yes, good choices> Zimmy P.S. Jason Kim at Aqua C is one heck of a nice man and has helped me out tremendously! I love spray injection skimmers. Plug it in a let it do its job. Great product and great company. <Yes, a fine person. I will relate your comments to him. Bob Fenner>

Lighting Fixture Question I recently bought myself a little gift a 46 gallon Bow Front. The problem I am having is working with lighting. The tank came with 2 light fixtures that have 2 Fluorescent bulbs in each unit I think there 18 inch bulbs. The question I have is that these fixtures are long enough to house a 96w PC and since it came with 2 of them I was thinking of installing 1 PC in each one (1 White/1 Actinic). What do you think? Do you think that the fixture would hold these as far as heat? The light fixtures are oak colored and are made by Perfecto. Thanks, John <Perfecto even provides CF lighting in these fixtures... you may have to modify the end caps to vent some heat with the 96 watt sizes though, but yes, a good plan otherwise. Bob Fenner>

Marine Aquarium Lighting... help greetings to the aquarium guru!! (that's you) hahaha. I was hoping that you might be able to give me some suggestions as to how I can improve on my tank, and what changes im going to need, or if im heading in the right direction for my reef tank... (Perhaps) I currently have a 37Gal tank 30"Lx12.5Wx23"T. I have an eclipse hood on it and I have a 55W power compact retrofit on it for the moment. my sandbed is about 3-4" deep and I only have about 15lbs of LR in it will soon have 40lbs more). I have a tiny air-driven protein skimmer in it at the moment, but I just bought a red sea Berlin hang on, I just built a new hood for my tank and will add a 175W 14K MH bulb, w 2 fans to cool it down, and add 2 standard 24" florescent actinic bulbs.  (Yikes... a shame to have not started with a larger tank...) I have a small maroon clown and a tiny yellow tang at the moment in my tank. I had some green button polyps in my tank & a coral frag (which I believe might be some purple xenia?) (Hmm, likely not... Xeniids are soft corals... typically 'pulsing'... and not purple...) both seem to be doing somewhat okay, at the moment, but the polyps aren't as good as when I bought them(2 weeks ago).. do you think the MH lighting setup im going to do is good enough? too much? could do better?  (You will soon see... need to ?grade into this{ amount of lighting... screen part with aluminum foil... to avoid burning your livestock... the type-amount will work out eventually... in a few weeks to a couple of months) what do you recommend I do? please help me, I came across your website and it seems you can help me a lot more than a lot of other places.. all the stores just want to make money off of me, but I haven't fallen into that trap at least not yet) any help you could give me would be greatly appreciated. thanks!! (I will gladly help you... Please do read-reread the sections on light, lighting on the Marine Index on the www.WetWebMedia.com site. Bob Fenner)

Lights< Smart, Dura... Bob I have been reading all of your posts on the subject of lighting and learning a lot. But I have a few questions that I most likely have read about but I am not understanding. I am new to salt water, I have had fresh for over 3 years and wanted a new challenge(?) or new fish not sure which? <There are many...> But I/we have switched our 55 gal tank to salt water. Right now we are going with a fish tank but my helpers are informing me that they like the anemones and I think some of the soft corals. So what ever I buy to upgrade my system I want to make sure I meet those future needs. Which leads me to lights. Like I said I have been reading your articles and FAQ on different web pages and I think I understand what I need. But I was wanting to know about the new smart lamps that have both blue and white lights in one. Is this a good package or should I get a system that I can put 4 bulbs in 3 white and 1 blue or 2/2 or ....  <One blue out of four is best> The smart lamps look like a nice match and are reasonably priced. If you don't think this is a good product. What do you recommend.  <These are very worthy products> I read one article that you stated that you liked Dura-Light. But I have been unable to find these on the web or locally. <Yes... older technology...> At least I don't think I can, I found the bulbs at a store do they also carry the fixture?  <The Dura-Light products (Vitalites, etc.) are/were Normal Output fluorescents... regular fixtures fit them... But do go with the Smart Lites, other power/compact fluorescent technology.> The store I found the bulbs at didn't have a fixture. I also keep reading that you like the 4 bulb systems does this mean you run two fixtures or do they make a 4 bulb fixture?  <Mainly two doubles...> I also have a canopy so I am using glass below my existing lights is this ok?  <Should be... do add washing, wiping them down weekly to your task list> My boss/wife like the canopy so :-):-) any advise would be great.  <I understand> Thanks for all of the great articles and time you seem to spend on this topic. Lou Feagans <Thank you for your kind words, and intelligent involvement in our hobby. Bob Fenner>

Fluorescent Lighting Hi Bob, I have a 72 gal bow front marine aquarium. It is a fish only tank with 2 standard fluorescent tubes. 1 - Hagen Power-Glo 48" 40w T10 ( Lumens 2200, Lux 180, Kelvin 18000K) The other is a Hagen Marine-Glo 48" 40w T10 Actinic Blue (Lux 105) <Okay> Is this lighting adequate? If not, what in your opinion is a better choice? <Adequate for? A fish only system? Yes... for one with live rock? No, you need about two-three times the amount of intensity (useful illumination) as stated. For most of the types of photosynthetic life folks keep? No, you need about three to four times the amount... For the higher/est photosynthetic life like many of the SPS corals, tridacnid clams...? No, you need at least four times this amount and five or six more times would be better/optimum... Please read over the "Light", "Lighting" sections on the marine index on our website: www.WetWebMedia.com and all the associated FAQs files here... You should come to understand the underlying science and technology and your options for getting the intensity and quality of light energy you're looking for such a size, shape system and purposes you intend, with what livestock you're considering...> Thanks always for your help. Ed <Study my friend. Bob Fenner>

Lighting for reef tank Bob, I am interested to maintain a 36 x 18 x18" tank with live rocks and under gravel filtering system. I plan to keep a wide range of mushroom corals, shrimps and macroalgae and clay fish also. <Clown?> As for fish I like the flame angel or African clown fish. <One's from Africa?> But I AM concern about lighting and the LFS only offer 2 type only. 1) 3' Coralife High Intensity Purified Super Daylight Lamp ( 10,000 k ) 2) 3' Solar Nature Full Spectrum Color Lamp ( 6,000 k ) from Germany. My question is which is most appropriate for reef tank and how many are needed for my case??? Thank you in advance. David. <Hmm, both would work... In fact I would use both, maybe one of #1 and one or two of #2 myself for the anemones that you may end up trying. Also do look into compact fluorescents for your new system. Much more on your lighting options can be found on the site: www.WetWebMedia.com under the "Marine Index". Be chatting my friend. Bob Fenner>

2 questions Lighting/Alkalinity Hi Bob, just wanted to say that I have been misled by many LFS stores in my short time (6 months) with the hobby and your website has helped me learn and avoid making the same mistakes. <Too much of all this going around...> I have 2 questions that I cant seem to get an answer too. I have a 72 gallon bow front with 4 X 96 watt PC. The tank is 6 months old and recently I started to notice a green algae buildup on the sand. I replaced all the lights. I purchased the new bulbs from Marine Depot. I switched to the 10,000K white and have the 6700 blue. I simulate dawn and dusk, but how many hours should the lights be on.  <The actinic on an hour ahead and after the whites... Actinics on about 12h/d, whites 10... can be stretched out, the whites put on a dimmer... or even one of them turned on at the same time (possibly) as the actinic...> When I replaced the lights the green algae dust that was on the sand went away. However, its back.  <"It" was/is not simply the lights... but "succession"... conditions favoring, allowing the green bit... and they fighting it out for space, light, nutrients, poisoning other life forms...> So im assuming it wasn't due to the lights, but I was told they should be replaced every 6 months, so im sure it didn't hurt to do it.  <Hmm, yes, but better to not replace all lighting at once... stagger lamps a month apart...> Right now I have the blue lights go on from 2:00pm-10:00pm and the whites from 3:00pm-9:00pm. What should they be set to? <Sounds good to me> My other question pertains to a PH spike I just had. Vie been adding iodine once a week, reef advantage once a week and phytoplankton every 2 days. But the other day my LFS said I should start adding Kalkwasser every time I add top off water.  <If you use it, and this is during the evening, and you can add it very slowly, yes> I read in some of your articles that Kalkwasser raises PH. <Of a certainty... calcium hydroxide solutions are very basic.> Im a bit confused, the LFS said they use it on there tanks and the coralline algae growth was phenomenal.  <Yes, a very useful dependency when/where used properly for boosting encrusting red algae> I also noticed my alkalinity was somewhere between 1.1-1.7, but its been like that from the beginning. I read on your site it should be higher. What are your thoughts?  <Yes, should be twice this... even more> Should I be adding the Kalkwasser? Should I be adding something else? My levels are: PH-8.0 Alk-1.1-1.7 nitrites are a bit confusing. I have a marine test kit and when I test the nitrites it comes out a color not on the chart, a sort of faded purple. amonia-0 Phosphates--0.2 Nitrates--again when I due this test it comes out clear, not a color on the chart. calcium-450-460 <Not adding Kalkwasser if your calcium is where you state, but other materials for boosting alkalinity... Or better/best utilizing a calcium reactor... Do read over the calcium et al. sections of the website: www.wetwebmedia.com and get your hands on v.1 of the Baensch Marine Atlas... this has the best run-down on alkalinity and biomineral relationships, uses. Bob Fenner> I appreciate your help! Sincerely, Steve Rubin

Fluorescent lighting: Best type? Bob, I Have gone through the FAQ's and other responses and have a couple of questions for lighting. I am planning on a having a heavily stocked reef only system. (maybe a few clowns and smaller fish). 1. I understand that I should use 3-5 watts per gallon. But is 3 watts per gallon like Microsoft saying that WindowsNTserver will run on a 486 with 24 megs of Ram? (yes it will but it kills the system operator and it really sucks) I already have 2 units 48 inch with two bulbs each (total 4 bulbs) at 40 watts each. Ready for my new 55gal(std aquarium size here) reef tank that has recently matured. Will this be enough? or is it really a trying to run a fortune 500 company on a 486? I have thought of changing them to the CF but did not fully understand the cost benefit of changing. <Like your comparison, and yes, it is quite apt on a few counts... more, much more to this "story"... The CF's would be better, even at par comparison of watts consumed or produced in lumen equivalence... the useful light produced by these different formats is not the same... sort of like the Intel CPU's with limited cache...> 1. In ranking the least to greatest beneficial usable light output where do CF's fall when comparing them to normal fluorescents, then HO and last VHO. I get different stories from my LFS. <CF's are at the top in terms of production (by watt-production, kilowatt consumed, overall cost per lumen/useful photon... of all these formats> Thanks, Sean Warren Could you respond back to this email so that I may read this while I am traveling. We must decide what we will do in the brightness of day before the night falls and the storms set in <Bob Fenner, who feels like he's in India with the above stmt.>

Still unclear on lighting?  I am still in need of a little help on the ACTINICS lights. I usually think of them as only as for looks only but in your response to another you recommended them are they of any real value in a FO tank or Reef tank? Here is the case were you recommended them. Pasted from your site. <Actinic lighting refers to certain wavelengths ("life-engendering", embodying "actinism", if you will) that are more specifically supplied by "actinic fluorescent lamps"... Are these useful to hobbyists, culturists? Minimally... as enough intensity/lumens/photons of this EMR are provided by most all other lighting modes... For some, mainly deeper-water (collected) organisms that hobbyists utilize, such specialized light production can be worthwhile... but is it "cost effective" relative to "higher Kelvin rated" light sources? Almost always never. Put another way, for the cost of acquisition and operation, neglecting esthetic considerations, actinics are by and large a waste of money for home aquarists. Why are they sold may be your real question? To make money. Why would I (or anyone) reply in a general way to a home hobbyist that they might/should add this sort of lighting? Because I/we have no idea of what they might now or later add to such a system... and yes, some animal groups (tridacnid clams, some Acroporids, Pocilloporids, Faviids...) do demonstrate discernible improvement with accentuating these wavelengths... plus a few other "reasons"... Bob Fenner> > We have just purchased a 110 gallon aquarium, with wet dry filter, protein skimmer and an additional power head. We have also just purchased live rock uncured and cured from FFE. My question is two part (we are novice) 1st I eventually want to add lighting for soft coral, etc. what would you recommend for this size tank. > <If only live soft corals, VHO fluorescents, possibly VHO and Compact Fluorescents (some of actinic, some whites of 5k, 10k temperature)... to Just CF's... If you might go the SPS coral and tridacnid clam route, possibly the addition of two, or even three Metal Halides in addition to some CF actinics...> > #2-The live rock will be coming today, since the tank has been running for over a week, can I cured the live rock in this tank? Please give me your opinion. > <Yes, do cure the live rock in place... see the articles on this and related topics stored at www.wetwebmedia.com> > Its great to know that their are professionals who are there to help > Thank you, Connie > <You're welcome! Bob Fenner>

Lighting?  We're the fish men YEAH! Bob I have read your book and carefully the section about lighting. My questions is this. After finishing I thought that the blue Actinic were of no value except to the human eye. However in the following response you gave you encouraged actinic. I have pasted it here. I am a little confused. I have a 125 (standard measurements.) and a 55. I'm planning the 55 to be a reef tank. Will 4x 48inch reg. 40 watt bulbs and the name brand recommended most in your book be fine for the 55?(the name slips me now but you really spelled it out very clearly). <Probably Dura Corp. (RIP) "Vitalites"... and time marches on my friend... these were the best lighting (to my knowledge) when the section was penned, later published in CMA (in the mid-90's)... compact fluorescents are far better functionally, aesthetically now... and in a few years? Beware of linear thinking and logic in this universe> Also the 125 is fish only with 60lbs of Fiji live rock. would 4 of the 40 watt bulbs be enough. (of course the name and model that you mention in your book. <Not in my opinion... look to the CF technology> Your humble Acolyte, Sean Warren PS. I would hope that this does not appear that I am being anal in taking what you say below here and using it to compare to what you say in the book. It is just that I have tried to consume every thing I can with your name on it, paying attention to every detail that I can. On a funny note I refer to you in virtually every sentence and I start out every part of a conversation with "BOB says ....." and my LFS said," Hey he is not GOD and does not know everything". I disagreed. Lighting <You are seeing things not there my young friend. I am only another struggling human. Of limited capacities, understanding and vigor. Life to you. Bob Fenner>

Aquarium Lighting Question Hello Bob, I have a 58 Gallon tank... fish, some mushroom corals... I am using 1 Power-Glo bulb and 1 Actinic bulb. All seems fine, but I need to replace the bulbs. Is there a better brand/bulb to use?... URI, Coralife, Triton... <All of these are better... and made by "other" people... Choose whichever is less expensive of the three in anything more than 5k K temperature. Further lighting input on our site: Home Page > Also, Any recommendations on what I can add to the tank to further develop the mushrooms? Vitamins, supplements? <The prep. solution Selcon is about all I'd add... via the food to the tank... about once a week.> Thanks, Terry >> <Be chatting, Bob Fenner>

Bob, Looking into CF lighting. Is there a hard and fast rule for how many watts you need? <Some, a couple/three watts per gallon on up... to several depending on depth of tank, types of livestock (SPS, Clams for more for instance), and desire (boosting metabolism say vs. maintenance) and pairing other gear, activities (supplying sufficient biomineral, alkalinity...)> I have a 225 gallon tank that is 6foot long X 2foot wide X 2 1/2 foot deep. <More for you... 3,4 w/g...> Thanks, Derek P.S. Still working on cooling issues!! Installed some fans today that I think helped. >> <Hotay! Bob Fenner>

Light Reports - GE & Sylvania? Recently GE and Sylvania have been advertising lights "10,000 k saltwater fluorescents". The prices are so low ($10 - $13.00 for 48", 40 watts) they raise suspicions - either these are cheap & useless, or we have been ripped off by the other "premium" suppliers. Has anyone seen any tests on these lights? Charlie >> Actually, these lamps have been "with us" for decades for other purposes... and the same companies (and two others) make the "premium" (i.e. relabeled/otherwise labeled) lamps... and the cost differences are mainly due to added layers of distribution.  The actual cost of production of fluorescent lamps is... quite low, the gear to make them, a few million dollars U.S.... just like oil/petroleum products, they're "free", until you go through the costs and mark-ups of production, packaging/labeling, marketing/sales and distribution. Bob Fenner, who begged Dura Corp. to allow marketing of their products in the industry for many years (the Vita Lite debuted in 1967).

Reef Lighting Hi Bob, I have a 125 gallon tank that I'm currently setting up into a reef tank (later adding certain reef friendly fish). The dimensions are: Length - 5ft, Width - 18in, Height - 2ft. I have been looking at different light fixtures and have decided to go with power compacts, mostly because of financial matters and heat build up with the halides. I was told that 2 daylights and 2 blue actinics at 55watts each would be sufficient, but that I could also step up to a 96 watt. What do you think?????  <Hmm, two feet deep... and what sorts of light-needing life do you intend to keep... Well, whatever mode of lighting, this is way too little intensity... you should plan on at least the 96 watters... maybe even more lamps...> Also I was browsing websites on lights and came across an article about Slim Line Lighting. This is how the article read: The latest state of the art type lighting using tubes about the same diameter as a pencil. Very powerful lights said to be equal to metal halides with no heat.......full depth 24" penetration and very low running costs. Bulbs give an average 8,000 hours use and the ballasts are guaranteed for three years. Unfortunately, the website gave no contact info what-so-ever :( Do you know anything about these lights available wattages, lengths, where to get them, etc)??????? Any info about this would be a great help because I am very curious about them. <Me too... have heard of the technology... yet to see it in use... or results shall I state... I would go with the CF T-8's in the here and now> You don't have to place this in on your web page or anything like that, but I would appreciate an answer as thorough as possible (Slim Line Lighting). Thank you so much for your time!!!!!! James >> <Do get around to previewing, then moving around the Q and A's of perceived interest on the WWM site... Bob Fenner>

Reef Lighting Choices I have a 110 gallon reef tank with two 175 watt 10,000K metal halides and two 7,100K blue actinic power compacts. I have both fish and the following corals: finger leather, mushrooms, xenia, frogspawn, Montipora digitata and a pink Stylophora. I have seen new power compact light bulbs advertised that are rated at 10,000K. Would there be any benefit to swapping the 7,100K actinics for these new bulbs? >> In my opinion, not enough to warrant the change, functionally or for looks. The mix of spectra you have now is fine on both counts. What is remarkable (so I'll mention it) is the effects of "other" influences on light transmission, absorption in your system that you can influence, notably "color" and dissolved organic compounds, and the depth/placement of your corals. These factors can exert a very large effect on the quality and quantity of light reaching your photosynthetic livestock...  Color and DOCs are best dealt with by way of a regular regimen of partial (half let's say per period) gravel vacuuming in concert with partial water changes, efficient protein skimming, and the use of activated carbon (once a month let's say) in your filter flow path. Placement is a huge subject, but basically concerns the raising/lowering of livestock nearer the surface and proximity of your light source to provide more red-end and higher intensity light. Individual specimens and species are seen to do better at different placement... and can be moved, but not too frequently (once again, let's say once a month maximum) in attempts to find their best positioning in a system. To sum up, I would consider the above factors and engage in efforts to maximize your success via their manipulation, but wouldn't change the lamps out (to something bluer) if it were me. Bob Fenner

Re: Lighting 2 hi, Do you recommend this set up I got it from www.garf.org To light my tank I know the hobby is very expensive I just want to save money:) This set up uses regular shop ballast to light VHO bulbs.................... ....From a standard, two bulb, non-electronic, P class, shop-light ballast there are 4 pairs of wires. One pair of wires (white and black) go to the outlet, another pair (yellow) go to one pair of end caps, and the other two pairs (one red pair and one blue pair) go to the other two end caps (blue to one, red to the other) in the standard setup. When using the standard setup with the standard ballast it is possible to run most if not all normal output (NO) 48" 40 watt bulbs; it will be difficult if not impossible to run two VHOs in this setup unless the ballast is no longer functioning properly. However if the end caps attached to the yellow wires are not used and the red end-cap is put on one end of a VHO and the blue on the other a VHO will operate as will a NO bulb, but it will look as intense as a VHO. Crossing the end caps of different ballasts (particularly single bulb 40 watt ballasts) can allow for a mixture of VHO and NO bulbs with fewer wires being left unused.  please let me know thanks again...you are very helpful. >> This arrangement may, repeat may apparently "work" for now... but is an example of "false economy" in my view... By using electronic ballasts designated for VHO lamps you will get more light, and your lamps will last longer... a better arrangement in the true cost for what you're getting... I would definitely NOT re-wire a shop lite ballast as per the above description. Save up and buy electronic ballasting... this is the route to go. Bob Fenner

Lighting  Once again I seek knowledge... I read your article on wetwebmedia.com about lighting in the aquarium and did some research on the web. I checked out the Dura-test webpage and couldn't really find a way to order just a few vita-lite bulbs for my tank.  <They're manufacturers... who don't sell to the end-user...> It seems everything that could be ordered was in mass quantity. Also in the area on their page where it talks about use with pets, the bulb it recommended was 20 watts. Is this really enough for a 125 gallon tank, even if I used a couple?  <No, but they do sell larger lamps, larger wattages, power twist (tm) types... The statement you saw probably referred to small mammals, birds...> I know that the spectrum of light is important, but I also thought that wattage was as well. <Yes, as interpreted as intensity... lumens... and per kilowatt energy produced...> I was thinking about using metal halide bulbs, but the cost and the heat factor seem to be keeping me from going that way.  <These are downsides> Plus, you didn't rate them too well in your article.  <MH are appropriate, even the best available, most appropriate technology for very deep (relative to hobby use) systems... with high-intensity light using organisms like SPS corals, tridacnid clams... but the modern Compact Fluorescent light technology can outdo them for function, cost of installation/use, safety.... in almost all cases... most public aquariums are switching to CF's or have done so...> I suppose a disadvantage too would be to have no top on your tank whatsoever when you hang the light from the ceiling. Even so, these bulbs seem to be less expensive than the compact fluorescent bulbs. Sheesh! Talk about forking out a lot of cash!!! I want to have more power than the two standard 30 watt 36" fluorescent bulbs I'm using now, but the choices seem rather confusing. I do plan to get an anemone down the road, and there does seem to be some coral growth on my live rock (it looks like two brown hairy flower buds that haven't opened yet, with tiny circular red mouths) so better lighting seems like the right way to go. Will 20 watt vita-lite bulbs actually work better than compact fluorescents?  <No...> How many would I need? How would I get them? Uhh... my brain is about to explode again, so I guess I should stop. <Don't explode... take a look at the CF retrofit kits FFExpress.com is offering... save up, and install these... this is the best route to go for your 125>  Oh yeah, one more thing. I'm trying to get my 3-stripe damsel out of the tank, but having 90 pounds of live rock in there doesn't help. Do you suggest any special way of coursing the fish into the net? Or should I use 2 nets? Any advice would be helpful, and thanks again. -Matt Lindstrom >> Always use two nets... one to drive the animal, one to lift it from the water... but good luck... maybe training this animal to eat above a "permanently installed net" might work... Bob Fenner

I have a 55gal fish/soon to be reef. I have 2 24" strip lights that hold 18" bulbs. Id like to know what type of lighting/bulbs I should get just to be able to keep a few small corals. Such as a brain or two and a torch or two.  I'd also like to be able to keep a derasa clam. I want the most inexpensive I can get. The bulbs in there now are 15w fluorescents. I was told that I could use a 50/50 in each strip light and one large blue bulb, is this true? I don't want to buy PC lights, too much $$ for my budget right now. Any info is  appreciated!! >> Hmm, well as big a penny pincher as I am (I've made tears come to a buffalo's, Bison bison, eyes by squeezing old nickels), I must remark that this isn't an inexpensive hobby... and that the tridacnid clams need lots (intense), full spectrum light of high Kelvin rating, high CRI... that generally can only be rendered (in a tank of the depth of a 55, 22") via VHO fluorescents, CF's and/or Metal Halides... The lighting you have now is, as you know/suspect, entirely under-powered... The least (initial) cost that can get you near what you want support (not much growth) wise is a couple of double 4 foot shop lights (very cha-heep) with full spectrum, RO (Regular Output) lamps... like 3 Dura Vita-Lites... and one Actinic... your choice of manufacturer... However, do/should point out the "false economy" of this approach... in the long haul (a couple of years)... you would/will be better off... cost of power, looks, function, replacement of fixtures... "just" saving up, investing in Compact Fluorescents... Bob Fenner

Lighting Bob,  I need to switch gears here for a minute. I know, don't add anything until my "problems are solved" but this has been bothering me. All my mushrooms look great, as do my colt, anchors, crystal, and umbrella. I have attempted to keep a cat's paw, a bird's nest and a breadcrumb sponge. All met the same fate. They became covered in algae and perished. Heck, even the Caulerpa I have in my tank has algae growing on it. After reading your WetWebMedia article on lighting, I wonder if this is my problem. My 75 has 4x96 PC that my wife turns on around 8:30am, and they stay on until 10:30 pm. This is the Hamilton fixture where one switch controls the left side, and the other switch controls the right side. I have a 6700, and 7100 on each side.  Should I rewire so that I can turn on one left and one right bulb with each switch?  If I do rewire, which ones 6700/7100 go on first, go off last? How many hours a day do you think I should run these lamps? Thanks, Marty >> I would rewire these fixtures... the lower Kelvin rated lamps should come on first, go off last, and twelve hours of these a day max. please... if you want them on late at night have a hiatus mid-day... via timers... Bob Fenner

Lighting with black lights, Good or Bad? I put over my tank a 15" black light, it brings out the colors in my live rock, and anemones really well, but I don't know if it is doing any harm to the rock, or the anemone. It makes the tank look good but I don't know if its helping or hurting. By the way I have a 55 gallon tank, and 3 other lights, two 15" white lights, and 1 36" white light, I am going to purchase probably two blue lights in the future. >> No harm... and possibly some demonstrable good... If the lighting is safe for use around humans, it will not harm ornamental aquatics. Bob Fenner

Lighting I know you are an advocate of full spectrum lighting. Will two VHO AquaSun 5200k (termed wide spectrum) and two VHO Actinic 8000k be appropriate for a 55 gallon tall tank that will hopefully be a long time home to some soft and stony corals, as well as fish and inverts? I was not able to find any full spectrum VHO lamps in the 36" length. ( Vita-lite has a 48") Thanks for your wonderful attention to the hobby. >> >> Hmm, take a look here: http://www.championlighting.com/ and get their real "full spectrum" lamps... not the ones above... in 36" lengths... Bob Fenner, who thanks you for writing

Lighting I have a 125gal fish/invert. tank with current lighting of two antic 03 40 watt bulbs and two 50/50 40 watt bulbs. I'm thinking of adding two 140 watt VHO bulbs to thisset up. What do you think about VHO lighting?? This would put total wattage to 440, might be a little short but metal halide is a bit expensive. If VHO is all right do you have any suggestions on good ballast?? I'm thinking of the Sun Seeker 2 ballast. >> This proposed addition is excellent. You will be very happy with the quality and quantity of light the tank will soon have. Regarding the electronic ballasting... I am a much bigger fan of the Ice Cap product: http://www.championlighting.com/ a proven winner. Bob Fenner

Reef lighting How many watts of lighting does a reef tank need per gallon. I have a 75 gallon tank. >> The watts consumed or rated is not much to go on when guesstimating needed/desired illumination for aquariums... for a few obvious and maybe a couple of unknown reasons... Turns out, different means of producing light are more/less efficient in terms of apparent and actual (useful) light yielded per watt (kilowatt hours actually) of electrical consumption... Further, the wattage-required if you will varies in the way of depth, other qualities of system water... And importantly, there is a wide range of what sorts of light/wattage-required depending on the types of light, and what you want it "to do" with a given system... Fish Only systems can be barely lit, SPS Corals, Giant Clams require intense lighting... Now getting down (finally) to some sort of answer... for your 75... probably somewhere in the 160 to 500 watt range... depending on... Just lighting a FO system on the low end... to midway for Fishes with Live Rock and maybe some low-light-using life to the Corals and Clams mentioned on the high end...  Could you "use" even more "wattage"? Yes, to drive photosynthesis, growth, even reproduction of some life forms... are you willing to put in all else that this "driving" requires? Manipulation, testing of water, addition of biominerals... Bob Fenner, who will gladly help you develop an algorithm to explain this answer mathematically

Lighting I currently have a Coralife SHO 48 inch strip and two 55 watt 6700 k I would like to keep clams, corals and invertebrates i.e.. anemones. Is this sufficient.  Do I need to add a blue actinic, the SHO light strips are expensive can  I get away with adding a single or double fluorescent fixture for the actinic.  I was looking at a RedSea Phazer IV, with two Aquastar 10k's and two Coralstar Actinic Blues what are your thoughts.  Confused Regards Lou >> I take it these are on a four foot or so long tank? Depending on depth (as long as it's not over 22", like a show model 55 gal...) the present lighting should be fine, and better with adding the actinics... even if they're normal output fluorescents. The newer lighting system proposed is nicer, but not necessary... for most collections of livestock I would have... unless you intend to push their metabolisms... and have the money, expertise to contend with the induced mal side-effects of doing so. Bob Fenner... who would just add the actinics.

End caps Bob - I need to get some end caps (waterproof) immediately. I currently have  the white ones that consist of three pieces that all screw together. I can  never get the bulbs to fire up without at least 2 hours of messing around.  It is driving me crazy. Any suggestions? Thanks in advance. Rebec >> Yes! And this is important... as annoying as it is to you to have to fiddle with the end caps, it is also a hazard to the lamps... and maybe you. I take it these are T-12 ("regular" fluorescents)... if you're not happy/satisfied with the fittings and ballast system en toto, do look into the lighting systems sold by Aquarium Systems and Energy Savers (ESU)... if only the end caps are bothering you, maybe contact Champion Lighting (http://www.championlighting.com/)... And for the hot tip of the day, before inserting your lamps, smear the pins and metal end pieces with a thin coat of silicon o-ring grease (like for camera gear, pool pumps...). This will help make a secure, water tight connection and ease their removal at a later date. Bob Fenner

If I have a 50 gallon Marine Fish Only system (plan to keep it fish only) but want to add live rock to provide improved biological filtration and nitrate removal. I am currently using a single fluorescent tube lighting fixture.  Do I need to upgrade my lighting to keep the live rock alive and well? I know for reef setups one needs much more intense lighting but for a fish only system that has some live rock and maybe some macroalgae what is the minimum lighting required for a tank that is 18 inches in depth? Regards, Alec  >> At least twice what you have now... of full-spectrum fluorescents... and if a modification of your present set-up isn't easy... consider upping the ante to a compact fluorescent instead... You can buy the parts (FFExpress even sells them!) and put them in yourself. One of about 10k temp. would be great, two would be bright, but better. Bob Fenner

I've been told that you can use VHO fluorescents on tanks up to about 24"deep, but more than that you need metal halides. Does it go the other way, too? I mean, if you have a tank that is only 12" tall, can you use regular full-spectrum fluorescents and still have a successful reef? To a large degree yes; though an answer to this sort of query must delve into a few statements of fact, definitions and qualifiers to be of real use. First, let?s agree that the intensity of light (number or quanta of photons) is the principal difference between full-spectrum fluorescents (FSF) and metal halide (MH) lighting sources. That is, both types produce adequate amounts of light in necessary and desirable (function and aesthetic) wavelengths to support and showcase captive reef life. MH is more intense, and thus able to penetrate to greater depths and provides more light to shallow ones. Whether this is critical or something you want though depends on two further major considerations: the type of life you intend to keep, and how much you want to "push" it. In aquariums as in the wild, there is a broad range of benefit and tolerance to more light. For example, Corallimorpharians (coral anemones), most of the photosynthetic gorgonians and soft corals (Order Alcyonacea) available to hobbyists get along quite well on FSF and compact fluorescents (CF) in the deepest of hobby aquariums. On the other hand, several of the popular true or stony corals (Order Scleractinia), do poorly unless provided either a roost in a shallower setting (with FSF, CF), or MH in greater depths. The "pushing" issue is a consideration of how much you want to enhance your organisms metabolic rates. Lighting, along with nutrient availability, conscientious filtration, and current are principal inputs to this physiological "driving". Do you want your Acropora for instance to grow about as fast as possible? Maybe it will become more spindly, less colorful, more short-lived as a consequence... Perhaps the cost of water testing, dosing and amelioration is only "worth it" up to a point. Each aquarist must ask themselves this question; "Per the species/specimen and environmental settings, what do I want my livestock to do?"| Obviously all light-affected life needs to be accommodated within its environmental tolerance; hence you must study and provide at least the minimum or at most the maximum amounts of light per that species/specimen in your setting. Such information is invaluable, and often more than just a matter of reading and chatting with other reef hobbyists and dealers. A tried and true approach for new introductions is initially placing them further down or away from the most intense light area, and moving them "toward the light" as they display a propensity for it. One last element of this "how much light will do/is too much" question I?d feel remiss to leave out is the effects of dissolved (mainly colored) material in the systems water. The cleanest of seawater absorbs, reflects and diffracts light; more and more with depth. The presence of suspended solids and various chemicals has an additional, often pronounced effect on diminishing photo strength. In practical terms, and for more than light penetration reasons, you want to keep concentrations of this matter to a minimum; principally through skimming, water changes and possibly the use of chemical filtrants. This is an area of discussion that merits much more emphasis and investigation.