FAQs about Caulerpa Algae Health/Disease Related Articles: Caulerpas by Bob Fenner, A closer look at Caulerpa - Common aquarium species and their care by Adam Jenkins, Embracing Biodiversity, Green Algae By Mark E. Evans, Green Algae, Avoiding Algae Problems in Marine System, Algae Control, Marine Maintenance, Nutrient Control and Export, Marine Scavengers, Snails, Hermit Crabs, Mithrax/Emerald Green Crabs, Sea Urchins, Blennies, Algae Filters, Ctenochaetus/Bristle Mouth Tangs, Zebrasoma/Sailfin Tangs, Skimmers, Skimmer Selection, Marine Algae, Coralline Algae, Green Algae, Brown Algae, Blue-Green "Algae"/(Cyanobacteria), Diatoms, Brown Algae,  Related FAQs: Caulerpa Algae 1, Caulerpa 2, Caulerpa 3, Caulerpa 4, Caulerpa 5, Caulerpa Identification, Caulerpa Behavior, Caulerpa Compatibility/Control, Caulerpa  Selection, Caulerpa Systems, Caulerpa Nutrition, Caulerpa Reproduction/Propagation, Other Green Algae, Refugiums,  Green Algae Control 1,  Marine Algae ID 1, Marine Algae ID 2, Marine Algae Control FAQs II, Marine Algaecide Use, Nutrient Limitation, Marine Algae Eaters, Culturing Macro-Algae; Controlling: BGA/Cyano, Red/Encrusting Algae, Green Algae, Brown/Diatom Algae,

White Growth on Caulerpa prolifica Bob, <Don> I am new to the hobby and have read through a lot of the FAQs on Caulerpa but didn't seem to find what I am observing. I have some newly acquired Caulerpa prolifica from another aquarium owner that seemed to be doing Ok for a few weeks. However, over the last week I have noticed that it seems to be either sprouting stalks of growth that look like white cotton in various places or at the broken ends of stalks (due to possible transport damage). What is this and is it problematic? Thanks for the great support and web site...Don <Mmm, can you send along a (very close-up) pic? This sounds like either a fungal (there are lots of these organisms in marine domains) colony growth, as you state subsequent to damage, or calcium accumulation at the apices... Either way, not really likely a problem... will probably self-cure. Bob Fenner> Caulerpa query   2/22/06 Hi Guys, <David> I have Caulerpa prolifera in a Miracle Mud sump.  The set up is about three months old and was doing nicely.  However the Caulerpa is disintegrating.  First the fronds appear covered in tiny hairs then these develop creamy coloured nodules at the ends and then the Caulerpa blade disintegrates.  I tried sending some pictures of this but I guess they did not go through.  The sump is lit 24 hours per day. <Mmm, I would check your water quality... particularly alkalinity and calcium and magnesium concentrations... and see below> I have read all about the problems of Caulerpa but living in the West of Ireland take what I can get.  Is this it going sexual?   <Not likely, no> Why would it do this? <Something amiss in the water most probably... or negative interaction with another algal species... chemically> Is it something else?  I have another macroalgae which looks exactly like terrestrial moss but cannot ID it, any ideas?. <Bingo... it's likely this other algae mal-affecting your Caulerpa> Neither can I get my hands on Chaeto. Thanks for your endless help. David <See WWM re the terms "Algae Allelopathy". Bob Fenner> Re: Caulerpa query   2/23/06 Hi Bob, <David> Thanks for the reply.   Alkalinity is 10.4, calcium 395 but I have not been measuring/monitoring magnesium. <Should be present in about a 3:1 ratio with Ca>   I add Reef Solution at 5ml per week, change 5% water weekly (IO Salt) and top up with Kalkwasser. <Difficulties with Kalk here very common...> Have you any idea what the other algae is?  The best description I can give is that it looks exactly like "moss". <... not much to go on... Perhaps a Derbesia sp. See WWM re Green, other algae identification> I will try attaching a picture of it again. It is dark green and the stands are "pinnate" it grows unattached in a bunch but has/can attach to the sand substrate.  It also has a very sweet smell. I sourced it from two LFS, one in Ireland one in the UK and neither new what it was just that they had it in their sumps, it "worked" and seemed very hardy. Thanks Again David <A pic or drawing would help. Bob Fenner>  

Re: Caulerpa query   2/24/06 Hi Bob, <David> I an trying to resend a pic of the Caulerpa and also of the unidentified algae. <Got them... both appear to be Caulerpa spp.> I am one of those who seen to have a problem getting queries through with attachments so we'll see what happens.  I have searched WWM for an ID on the second algae to no avail. Thanks David <The second may be C. pinnata... See the Net or Baensch V. 1 Marine Atlas, p. 302... perhaps C. flagelliformis in its "small" stage. Bob Fenner>

Caulerpa Crash Question - Get it to Grow? >Hello WWM Crew, >>Greetings, Marina here. >About 3 months ago I had the Caulerpa start to crash in my ecosystem sump due to me messing around with the light quantity.  It has been declining now and it is down to a few sprigs on the bottom.  Is there a way that I can get it to start growing again?  Should I remove it all and go buy a fresh handful? Thanks! >>I would prune it to only what's actually growing/living well.  Then I would address lighting issues, which shouldn't be all the important since I've had no trouble getting it growing vigorously under normal output fluorescents.  Marina Moving Towards Success...  I have a marine 55 gallon setup and have had little success in keeping up with everything.  <Not to worry...It's all part of the fun and frustration.. er- challenge- of reef keeping!>  Essentially I can't seem to keep the Caulerpa alive in my ecosystem 60 without getting a huge green algae bloom. I'm also finding that when I leave the light on it creates more heat causing more evaporation and the final chamber drops down to lower than the Rio powerhead pushing the water back into the tank. That usually happens anywhere between 1 and 3 weeks.  < It sounds like this is more of a problem with the mechanics of your system than with the Caulerpa itself. I'd try to maintain a slightly higher water level to begin with, which might help. Maybe you could also move the light up a bit to try to lower the heat level. I've also read of some people sealing the opening on the sump to encourage C02, but I'd try plan "a" first. And, if Caulerpa doesn't thrive for you- well, not the end of the world, IMO. There a lot of other, more desirable and useful macroalgae to culture, like Chaetomorpha, which are virtually "bulletproof" with regard to propagation, and don't have some of the same drawbacks as this algae.  Could you point me to a good article on the proper way of curing live rock?  <Start with this set of FAQs: http://www.wetwebmedia.com/lrcurefaqs.htm You can also find lots of good information about curing live rock in Anthony and Bob's "Reef Invertebrates" book>  I'm thinking of setting up a tank in my office and was hoping to do a reef tank but I'm really gun shy after what little success I've had with my 55 gal. at home. I have what I consider to be a very unhealthy amount of bristle worms and brown algae everywhere. I just want a very healthy, relatively low maintenance setup. Any thoughts.  <Yep- just find some good basic methods, as found in a variety of WWM and other sources, and stick with them. Combine a good technique with fundamental husbandry techniques, such as aggressive nutrient export practices, and you'll be fine. A great book to start with would be John Tullock's "Natural Reef Aquariums", which is loaded with information on simple, sound practices to help establish successful systems!>  Thank you. I've found your help very informative in the past.  Jeff Longmore  <My pleasure, Jeff! Good luck and have fun! Regards, Scott F>

In Need of Weed? >I currently own a 20 gallon tank with an ecosystem hanging on the back with 5 pounds of "miracle mud".... >>Ok. >Here are the contents of the tank: 30 pounds live rock clown fish banded coral shrimp 10 hermit crabs 4 snails I can't get Caulerpa to live in the ecosystem...it keeps dying..... is there not enough waste for it to survive on yet?   >>I couldn't tell you that, as I don't know how long this has been set up. >I want to start adding some reef contents such as mushrooms and maybe a xenia....but I wanted to wait for the Caulerpa to live? >>Honestly, I've never had a problem growing it.  You haven't mentioned lighting at all, and if you wish to keep other photosynthetic organisms, this is of utmost importance. >My measurements seem to be ok.....I have only measured ammonia nitrate nitrite salinity pH >>And...?? >All of those are ok.... >>That tells me nothing, my friend. >The tank is about 3 months old now and water looks great? >>Ah, very new setup, you're not sure of how the water "looks"?  Looks can be deceiving, as I know of no one who can see nutrients, ammonia, etc., in the water just by looking at it. >Why is the Caulerpa dying...isn't it basically a weed?   >>It can be when its needs are met (light and nutrients). >Does it feed strictly on the waste in the water?   >>No. >That is all I can think of.... >>I can't be of more help without knowing more about your setup, filtration, LIGHTING, test results, kit brand (more important than most folks think), LIGHTING.. did I mention lighting?  I grew MUCH C. taxifolia in my first reef using a homemade bank of mixed fluorescents.  It took a good deal of research to determine lumens and color temperature, though.  Sometimes, some folks just CAN'T get this stuff to grow for them, though, no matter how they try.  Marina     

Caulerpa Concerns I have a large amount of Green Grape Caulerpa (identified by picture in Marine Aquarist). Great book and should be every aquarist handbook! Felt real comfortable with water conditions and clear water. Algae came in on some live rock and has thrived. <I wish my rare Acropora would be so hardy!> Several days ago started noticing some die off (small section of algae turning clear) in high flow area. Bob's book states that most macro algae like more stagnant conditions. This coincides with running return line from tank to sump over Poly Filter. I assume I should introduce some nutrients since Poly Filter is probably eliminating some the algae had been utilizing. (have not started doing so). <Eliminating the nutrients, no doubt...> Also I was going to trim back areas that showed signs of die off since algae was growing out of control. This morning I checked tank and water was cloudy. Nothing in sump area looked out of whack, so closer look showed a couple of spots in algae shooting (for lack of better word) a greenish, cloudy stream. This is a fish and live rock tank and was curious if something in water parameters triggered this? Will it clean up itself through skimming and filtration? Main question, are the fish in trouble? <Sounds like the Caulerpa are going "sexual", releasing their reproductive products into the water. Many factors trigger this reaction, ranging from temperature to lighting, to water flow. The depletion of oxygen in a massive event can lead to problems for the fish, so do engage in some water changes and continue aggressive skimming> They ate normal this AM. I also run CO2 reactor (about a month) and inject ozone through skimmer controlled by controller.  Thanks for any help.  David Stanley <Well, David- as discussed above, just stick to aggressive nutrient export processes, and you should see things clear up...Regards, Scott F.>

Continued Caulerpa Concerns Scott <Hello again!> Thank you for your reply. Things cleared up quickly. My skimmers overflowed a little and I am sure Poly Filter helped. Ran diatom filter in afternoon just in case.  <Both good moves on your part!> My plan is to prune back and keep it under strict control/boundaries. I would like your take on keeping Caulerpa at all. With fish and feeding, I thought might be food source for fish?/nutrient export benefits. <It can be a food source for many herbivores, and it can be a good nutrient export vehicle, if properly harvested and kept in check. As you now know, Caulerpa does have a "dark side", and can "go sexual" when conditions favor it. Also, Caulerpa can be very invasive to sessile inverts, often smothering or growing into them. It has the potential to release compounds which can be noxious to many corals.> It is not in there just to prove I can grow it. My coralline algaes are much better to look at. But being in main tank there will be day/night cycle with lights and from what I have read on your website, Caulerpa is recommended more for sumps or refugiums where lights can be left on? <Well, you'd usually run your sump or refugium lighting in reverse of the display tank's lighting. This helps keep stable pH values and provides an opportunity for proper growth.> Is this going to be on going problem? David Stanley <Well, David- Caulerpa can be problematic if it is not controlled. Many, many hobbyists use it every day with no problems. I like the stuff- I just don't want it in my tanks! I favor more "passive" algae, such as Chaetomorpha, and the challenging Gracilaria. Both excel at nutrient export, with none of the nasty potential of Caulerpa. And, Gracilaria has the added advantage of being just about the best food available for tangs! Well worth considering. Good luck! Regards, Scott F.>

Dead Caulerpa/Cyanobacteria Questions (5/21/04) Hello Crew, <Steve Allen today.> I have a 50 gal reef tank where I have been battling reoccurring plagues of Cyanobacteria. As of 2-3 weeks ago, I put a couple handfuls of Caulerpa into the tank, which started to do well. <Ugh. I know there is disagreement among the crew about the value of Caulerpa compared to other macroalgae. Caulerpa has some real pros, but I think all would agree that it should be in a refugium, not in the main tank. IME, it grows like a cancer in the main tank, with the potential to choke of all other algae and even corals.> 3 weeks ago it started to disintegrate. <The downside of Caulerpa.> My protein skimmer was producing a lot of smelly waste, about 1/2 to 1 cup a day. I removed as much of the dead Caulerpa as I could find. <Good> Apparently, much of the waste accumulated in between the rocks and the sand bed. <Yes> Lo and behold, the Cyanobacteria made an appearance and has not left. <Thriving on the byproducts of the decay.> Trying to get a handle on my problem, I have read a lot of info and performed a 15 gall water change with RO/DI water. I have come up with a plan to get this tank back on track and want to know if my course of action makes sense. The tank has 3-4" of Southdown sand, 96Watts of CF 50/50 and 96Watts of Actinic 03 all 1 months old, about 600 gal/hr circulation into a sump which is the source for a 2 1/2 ft high venturi PS built by myself, and about 20lbs LR and 15lbs of dead rock. No purple coralline has been able to grow in this tank, I believe due to high phosphates and low Ca levels. No corals are in the tank because of the cyan. Salt - Instant Ocean S.G. = 1.025 Alkalinity = 10dKH Nitrates = 10ppm Nitrites = 0ppm Ca - 120 !!! <Are you sure your kit is correct?> Mg = 1320 P = <.01ppm (Seems low but probably due to the test only measuring for inorganic Phosphate, while the organic Phosphate is taken up by the Cyano right? 4 fish = 1 Royal Gramma, 1 Azure Damsel, 1 Male and 1 Female Anthias I performed a water change of 15 gallons, cleaning under all the rocks, scrubbing them, and removing any traces of Cyano. Another change of 12 gallons was made 3 days later after siphoning any remaining Cyano. My plan is to first use Kalkwasser and SeaChem buffer to elevate the pH, Alkalinity, and all too low Ca levels. <Read carefully how to do this. Another good option is B-Ionic 2-Part supplement.> Could this have caused the Caulerpa to die off and thus release the organic phosphate? <Hard to say, Caulerpa can be touchy. If it crashes or goes sexual, it can wipe out your tank.> Meanwhile I will be keeping an eye on the skimmate from the PS to ensure it is operating optimally. I am hoping this will provide the proper water quality to re-introduce the Caulerpa for nutrient export. <I strongly recommend against putting Caulerpa in the tank. It's too risk. Much easier to tend and prune in a refugium. You should consider a CPR AquaFuge if no space is available in your sump. Personally, having experience with both, I'd say you're better off with Chaetomorpha. Mine grows like gangbusters in my 25" AquaFuge with 65W PC lights.> When should I reintroduce Caulerpa into the tank, water parameter speaking? <Refugium> Secondly, once the Caulerpa becomes established, start to change the LR with newer pieces to repopulate the microfauna diversity. <The stuff will completely cover your rocks & sand with a carpet of Caulerpa. It is a prolific marine weed, ivy-of-the-sea so to speak. It is useful if carefully tended in a refugium, but it's a big messy pain in the main.> At this point I hope to be in the position to start adding corals like I once did prior to starting over from a previous Cyano plague (different skimmer and bioload). Any advice you could give me would be greatly appreciated. Glenn Koenig <Buy and read Anthony Calfo & Bob Fenner's "Reef Invertebrates." It has a fantastic 100-page section on macroalgae and refugiums.> 

Crab ID & Caulerpa Hi Bob. Firstly I would like to say how much I find your book helpful, it is one of the best books on the market. <agreed... WWM author Anthony Calfo> Now down to business. 1. Could you please identify the crab I have sent in an attachment,. It is about 1 inch across. <many such crabs are impossible to ID to the genus let alone species level for all but the Taxonomists. What you need to know is if it is safe or not. This crab by form and function that follows is clearly omnivorous leaning toward predatory. It may never cause a problem in your tank or it could begin nipping fish and coral tomorrow. As a rule... very few crabs are reef safe and larger clawed species like this may not even be safe with small fishes> 2. I discovered a few small snails the other day. They are grass green, both the snail and the shell. The shell is shaped like a scallop shell. At present they are about 1/4 inch long. <need a better description or pic, but do reference the shape of Stomatella species> 3.Tentacles keep appearing from the live rock. About 3 or 4 from the same crack. They are ringed (Black and light green) and about as thick as a piece of cotton. At present they are about 1 inch long. <many possibilities, but Ophiuroid starfish (baby brittles) commonly filter feed by sticking banded arms out into the currents> 4. I set up a plenum attacked to my main tank and placed some Caulerpa (Green looks like fern leaves about 3 inches long) in the tank, after about four weeks, the Caulerpa crashed. The water parameters are all fine, any possible idea what could have caused this? <Caulerpa is a miserable plant for refugiums for this and many other reasons. I would only recommend it in small quantities (any other macro instead please!). To answer your question... it likely had acclimation shock from the transplantation (too many broken branches sapped the cluster). Or it went sexual (a problem with larger colonies too that can kill your whole tank).> Many thanks Colin <best regards, Anthony>

Transplanting Caulerpa G'Day, 5 days ago I added some Caulerpa sertularoides to my FOWLR. I got 6 5 inch runners each had what appeared to be roots. I placed the root parts by putting them firmly between some l/r. now some of the tips of certain blades are dying off (turning white & some are clearish) should I leave it be and let the algae get a foothold or should I remove it. <I would let it go and see what develops.> 3/4 of it is still a nice lush green and only a few tips are white. I don't want to just cut off the white bits as this would mean cutting the actual blades. not enough growth to pull runners. it is in a 120 gal so a bit of die off won't affect my system but I want it to grow and if these runners aren't going to make it I can replace them but hope this bit of die off is normal and these runners will survive. thanks very much <Not unusual for it to take a couple of days to settle in. It has been 5 days now, so hopefully you will begin to see a difference, for the better. I agree that a complete die back will only affect your system minimally. Do be sure your skimmer is working well and maybe add some activated carbon to suck up any noxious compounds being released by the Caulerpa. -Steven Pro>

Caulerpa We have a 55gal reef and fish tank. So far have had very good luck growing and maintaining grape Caulerpa. However, even with regular trimming it has taken on a pale appearance. It appears to have a brown film covering it. We have recently treated the water with Phosguard, to help the invertebrates. I s there any way to save/ improve the appearance of the Caulerpa without increasing the phosphates in the water.? We have a product called GROW-IT which contains phosphoric acid, is this going to increase the phosphates?  Should we use it? Thanks for your help  >> Take a look at your alkalinity and calcium concentrations... Don't use the Phosphoric Acid (yes it will increase the phosphate in your system), and you should be able to dispense with using the chemical filtrant as well... The Caulerpa will jealously remove any excess phosphate. Bob Fenner

Problems Growing Caulerpa Hi Bob I need your help!! <Actually... your own...> I would like to grow feather Caulerpa in my main tank. It just lasts a couple of days and the dies off. I have been trying for a while but can't seem to get it right. Also, the calcium doesn't rise above 300 ppm. No matter how much Kalkwasser I add. <And it won't... you need a firm grounding in the related phenomena of alkalinity, pH and biominerals in seawater and the mal-affects of mis-supplementation. Please read over each of the above on our site: www.WetWebMedia.com and the references listed/mentioned on the FAQs associated with each article...> Thanks for your help, Alexis I have an 80 gallon tank. It is 3 years old & has a wet/dry filter system . LIGHT: One 175 watt 5500K Metal halide with reflector installed along with two 48"VHO bulbs actinic & Aquasun). They are on for 10 hours. WATER TESTS: Ammonia/Nitrate/Nitrite is 0 Phosphate - 0.1ppm pH - 8.4 Alkalinity - 1.7 ppm Calcium- 300 ppm (I know it's low!!) <Both the above two are too low... and likely your magnesium as well...> SG: 1.023 Temp: 86F EQUIPMENT: Seaclone Skimmer Water Circulation: Two Mag 802 powerheads with a Natural Wave Timer Sump Pump: Mag Drive 700 BIOLOAD (very low): 2 Royal Gramma) 1 Blue Damsel 1 Squirrelfish 3 Brittlestars (up to 6") 100's of small ones Misc scarlet and blue hermits Misc Turbo snails (about 15) 3 Carpet anemones 1 6"X12" rock with Sea mat 40 lb Live Rock 4 Sea urchins MAINTENANCE: 20% water change every two weeks I prepare a 5 gallon mix of Kalkwasser and use a peristaltic pump to add it. Weekly add KENT Iron/Iodine/Strontium&Magnesium Activated Carbon Bag in Sump <You can do a few things here... as you will find out soon. We'll be chatting. Bob Fenner>

Caulerpa Dying...What to do? I noticed in your FAQ that you said to add a tablespoon of baking soda with the system water, does this help the Caulerpa?  <In general yes... particularly in cases (water conditions) where alkalinity is in short supply... and/or there is an abundance of biomineral (typically calcium)> I've had a similar problem trying to grow Caulerpa in my 120 gallon mud system. <Ah, yes... especially in "mud" filtration systems. Do investigate alkalinity as a concept, use a test kit...> Thanks for a great web site, Ken <Thank you for helping by adding to it. Bob Fenner>

Caulerpa I had a quick question about Caulerpa. I had been running my sump with Caulerpa on a 24 hour day light schedule. Yesterday some of my macro algae starting to "melt" and release their green color in the tank. <Yikes... not a good sign... best to cut the material back about half... and do a massive water change... with hopefully pre-made and stored water: http://www.wetwebmedia.com/water4maruse.htm... to reduce stress...> I have 2 types of macro algae in my sump, razor Caulerpa and Halimeda. I suspect it was the Halimeda that "melted". Can I know what I'm doing wrong and if this cloudiness in my tank caused my the melting Caulerpa harmful to my corals and fish. Thanks again. <Could be trouble... either a reproductive event (the 24h/d light cycle should have prevented this) or "something" not in agreement with the macrophyte/s... Would also add activated carbon in your filter flow path... keep an eye on your livestock... you may have to move them... quick. Bob Fenner>

Caulerpa Dying...What to do? Bob, Great, informative Website.  <Thank you... how'd you find us?> I have a 50 gal. reef for 2 years w / 2x96w PC lighting (10k & 03), Berlin Classic Skimmer w/Dolphin Tankmaster 800, about 50lbs LR,  <Is this LR all original? You likely would benefit from adding some new> 2" LS, overflow goes into a recently built, 10gal refugium w/Double Mini-Mite lighting 24/7 w/ 1" DS, to return via a Rio 2500 to a spray bar in back of the LR and through a 4w UV hang-on. It seems that every time I put any species of Caulerpa in the tank or refugium, it appears to disintegrate in a matter of a 2 days by breaking apart, turning white or brown. I have read about the plants turning sexual, but this fast. <This is not the cause> I suspect it is lack of some chemical or tank parameter. My nitrates have been consistently high around 30ppm, along with Ca at 400, Alk around 9dkH, pH at 8.4, Phosphates are close to 0. I perform a 20%, 10gal RO/DI water change every 2 weeks with the addition of Kent Iodine, Strontium and Coral Vital trace, <Stop using this product... it is very likely adding to your problem... you don't need more simple sugars added to the water> 2 Fishes Ca/Alk every 4 days. My livestock includes 1 Yellow Tang, 1 Maroon Clown, 1 Hippo Tang, 1 Yellow Tail Damsel, 1 Sand Shifting Star, 6 Trochus Snails, about 8 Red Leg Hermits, Hammer Coral, 2 Bubble Coral, Candy Cane, 2 Open Brain, Ricordea, 3 shrooms, Yellow Polyps, Green and Brown star polyps, snake polyps, Button polyps, Toadstool leather, and a Pulsing Xenia...All doing great. I have added some Kent Iron to the tank but am hesitant to add anything unnecessary. What could possibly cause such disintegration? BTW, the same thing happened before I upgraded the lighting from a NO 10k and an 03. I did put in a red type of plant on a rock from my LFS a while ago. It has survived but does not seem to grow. Please let me know what I should do to keep these macros. Glenn Koenig <Hmm, some"thing" is missing here... as you state. I would cut the "vital" out, add a tablespoon of ordinary baking soda once a week (dissolved in some system water), add a unit of Chemipure or like to your filter flow path, AND a pad of PolyFilter... I suspect either a surfeit of ready alkaline material, and/or a spurious large amount of metal... perhaps iron... The stopgap measures mentioned should prepare your system, water for another Caulerpa "try" in a month or so. Bob Fenner>

Caulerpa problem Good morning Bob, Glad to have you back. It seems that your absence has caused a lot of people to go into "Bob Withdrawal"! :-)  <Saw this. Missed my friends here as well.> Well, since the last time I've emailed you, I've added some grape Caulerpa to my continuously lit sump, and added 4 turbo and 12 Astrea snails, and 8 red leg hermits. I've also added another small powerhead and switched to RO water for top off.  <All good changes, additions> All this to battle the diatom outbreak in my tank. My question is, on my grape Caulerpa, half of it seems to be thriving, growing new buds and extending it's stem, but the other half has shrunken down, lost it's color, and looks like it's covered with brown patches. Is the diatom killing the Caulerpa? <No... but that patch is dying... no worries> Should I move the Caulerpa to the main tank where there's better lighting (although not on 24 hrs/day)? Light on the sump is the cheapy 2-15watt hood that came with the 10gal hospital tank. I switched out the bulbs with 2-15 watt CF bulbs. Thanks in advance for the advice. <I would leave it where it is. The "rest" will soon need to be trimmed. Be chatting. Bob Fenner>

Re: Caulerpa problem Thanks for advice Bob. Ahhh, my arms have stopped shaking now that I've got my "Bob fix". :-) Forgot to ask, should I remove the dying portions now, or will it revive?  <Unless very decomposing/decomposed I'd leave it all as is. If removed, pinch off bad parts with your fingers, crushing thalli/"branches" in the process> Also, when (hopefully) the Caulerpa in the sump needs to be trimmed, can I feed the trimmings to the fish in the main tank, <Yes> or would this release the nutrients absorbed by the Caulerpa back into the tank? Thanks again Bob. It's good to have you back. <And to be so. Bob Fenner>

Caulerpa Hello again, I¹ve told myself that I will try to stop sending you questions, but I keep thinking of more. I really appreciate your advice. My questions this time are about Caulerpa (grape) algae. I recently purchased some from Marine Depot Live. The rock came nicely covered in the algae (it also came with some Halimeda algae). The Caulerpa has now thinned out a lot. It turns white and appears to disintegrate. I have done some research about this and have talked with Marine Depot Live. Everything appears to point to the plant going ³sexual.² First off, I would like to know the details about this process. Could you give me some information about this? <Please read over the WetWebMedia.com site re macroalgae> My water quality parameters are: Temp.: 72-78s F pH: 8.0-8.5 SG: 1.0245 Ammonia: 0 Nitrite: .025 ppm (high, I know, currently working on this) Nitrate: 0-2 ppm Silicon: .3-.4 ppm silicon oxide (about .75 ppm silicon) Phosphate: Trace to nothing Calcium: 450-500 Alkalinity: At least 7 dKH The tank (a 40 gallon) receives sunlight (some direct) from about 8:00 until 4:00 and then is lit by 2x96w compact florescent lights (one actinic the other full spectrum) until about 10:30. No supplements are added to the aquarium. The algae is located about 16² from the light (directly underneath the full spectrum) and 4² from the front of the glass. Part of the algae appears to be growing and the Halimeda is doing good. Do you think that the sexual process is hurting the algae? <No> Should I remove the dead sections (most of my research says yes)? <I wouldn't at this point> Would you recommend leaving the lights on for 24 hours? <Not necessarily. RDP is fine, or just as you have. Bob Fenner> Thank you, Kevin

Caulerpa dying Dear Bob, I'm trying to raise some Caulerpa racemosa to supplement the diet of my Naso tang. I'm keeping it in breeder boxes so he doesn't snarf it all up. It seems to last nicely for 2-3 weeks each time and then loses turgor and dies. I'm raising some in my hospital tank and the same thing is happening. We just installed power compact fluorescents in them main tank and the stuff is beginning to die in both tanks. Here are some other alternatives for why (that I've read on forums). 1.not enough oxygen in the breeder box-The stuff under the bubble wand is growing better. Still, the stuff in my hospital tank gets plenty of circulation and it's dying. <Not oxygen... maybe actually too much O2... perhaps this AND not sufficient CO2... but more likely...> 2.needs iron or iodine or other supplement--It dies after several weeks makes me think it's not getting something it needs. We have a protein skimmer which is supposed to remove nutrients. <Do you have sufficient alkalinity?> 3.not taking root-This time I put sand in the boxes and the stuff I pulled out due to loss of turgor seems to have taken root. 4.nitrates leech out so that there is too high a concentration immediately around the plant which does not diffuse into the system because it's in a breeder box. Again, my hospital tank has lots of circulation. <Not this either> 5.covered in algae that cuts off light--that happened in the beginning. This red filamentous stuff covered it. I cleaned it off every day. Now the red filamentous stuff is growing in the system but not on the Caulerpa. <Not likely> 6.too densely packed in the box-the box with the less densely packed Caulerpa died first. The leaves at the bottom seemed to lose turgor first but this was not always the case. <Mmm, no> I got a bunch in my hospital tank that is beginning to die so I can experiment. I got lots of live rock there too. It's growing under regular fluorescents but given that both the stuff in the main tank and under the fluorescents are dying at the same time, I can't believe the loss is due only to the light. I have some iodine, Kent Tech CB, essential elements supplement. How in the world can I get this stuff to grow??? I've tried 3 times now and it just won't work. This time, I'm getting a bloom of diatoms and red filamentous algae as the Caulerpa dies. <I would try other species, sources> Nitrites (near 0), nitrates (high 25-50 with Salifert test--this has been a persistent problem but I'm working on it), pH(8.3), temp(79 but varying a lot lately--used UV because tang was getting a bit of white spot). I just want stuff from my tang to nibble on during the day and hopefully my nitrates will be better controlled. I've tried every snack I can on this fish (several Nori types, lettuce, bok choy-several varieties, Sprung's sea veggies of several colors...you name it). This is the ONLY stuff he seems to like. Thanks, Allyson <Do look into some of the brown kelp/algae as well... Take a read through Baensch's Marine Atlas v.1 re Caulerpas... Bob Fenner>