FAQs about Acroporid Corals 1 Related Articles: Acroporids, SPS Corals,  Related FAQs: Acroporids 2, Acroporid Identification, Acroporid Behavior, Acroporid Selection, Acroporid Compatibility, Acroporid Feeding, Acroporid Disease, Acroporid Systems, Acroporid Reproduction, Stony/True Coral, Coral System Set-Up, Coral System Lighting, Stony Coral Identification, Stony Coral Selection, Coral Placement,  Foods/Feeding/Nutrition, Disease/Health, Propagation, Growing Reef Corals,  Stony Coral Behavior, SPS Identification, SPS Behavior, SPS Compatibility, SPS Selection, SPS Systems, SPS Feeding, SPS Disease, SPS Reproduction, A beautiful Montipora growth in the Red Sea.

Acroporas turning brown Hi WWM! <Hi Jen, MacL here with you tonight.> I know you all are so busy these days, I have tried to research this on my own and can't really find a lot of info on Acroporas turning brown.  I have asked several online dealers and the LFS, but I get very conflicting information. <I can tell you right now that's because multiple things can turn the corals brown.> I have been told I didn't have enough lighting (when I had 2 X 150W HQI MH), and upgraded to 2 X 250W HQI MH, and now have been told I have too much lighting. <Did you acclimate the corals to the stronger lighting? By acclimate I mean did you give them time to grow accustomed to the stronger lighting by putting them on for less hours or perhaps higher above the tank?> I don't know how much info you need to be able to tell me why this is happening, but here goes. . . 80 gallon tank, setup three years ago.  100 lbs. of LR, 60-80 lbs. LS, Lighting: 2X 250 W HQI MH 14k, 2X 96 W PC Actinics, mounted 10" off top of tank.  Aqua C Remora Pro (upgraded skimmer 6 months ago), 4 Maxi-jet powerheads, approx 920 gph. Livestock: 1 blue tang, 1 royal Gramma, 1 lawnmower blenny, 1 six line wrasse, 1 citron goby, 3 blue Chromis, 1 cinnamon clown, 15-20 Turbo snails, 10 Nassarius snails, 20 Astrea snails, 25 various dwarf hermit crabs, 2 blue tuxedo urchins, 2 Mithrax crabs, 5-10 Cerith snails, 2 brain corals, 1 Favites, 1 Blastomussa, 1 Montipora (also turned brown), 1 Acropora, 1 yellow Porites.  The Acropora and the Montipora are both near the top of the tank, top 10".   Water Parameters:  PH 8.3 1:30pm, Temp 80, Amm 0, Trites 0, Trates 0, Phosphates 0, Alk 8.4-9.2 DKH, Calc 375, SG 1.025. I use RO/DI water for top off and water changes.  I top off with one gallon every night.  I change about 5 gallons per week.  I use Kalkwasser,  turbo calcium, and Warner Marine's two part A and B.  I also started adding this week Kent's Essential Elements (which I was told I should be adding every week).  <Your levels look great but let me ask? are you having any ph fluctuation? Also, how long after you got the corals did they turn color? How long had you had them? Do you have any idea if they are wild corals? Often wild corals turn colors but will often regain color after they adjust to the tank.  Wild Acroporas will often change as part of their adjustment. See what I mean by it could be a lot of things?> Please let me know what you think may be causing these corals to turn brown.  I have also read "high nutrients" can cause this browning. What nutrients?? <Phosphates can be a problem but generally high nutrients are what they call the "dirty tank" which is often lots of algae, plankton, etc.>  Where are they coming from?  How can I test for them?  If I was overfeeding wouldn't I see a rise in nitrates and phosphates?  I am just completely confused and my head is spinning with what everybody has been telling me, please set me straight. <No worries Jen, I think the most confusing part is  that Acroporas can change because of many things and the biggest thing is just to go down the list one thing at a time to try to isolate what did it. Don't worry we can help you.>  Thank You,  Jen Marshall     Acros only open at night 11/26/04 Hi all, <cheers> I have read every thing I could find on your site and I still can't get the answer I am looking for. First let me tell you about my setup. My 55 gallon tank has been running for 18 months with DSB, remora skimmer, 15X circulation, PC 260 watts (lamps 5mths old), mech. filter for charcoal and lots of live rock. My measurements are 1.024,0,0,0, ph 8.35, pH .05, temp 80, cal 400 and alk 8.5. All test are double checked by my LFS once a month. I have a clown, flame angel and a hawk fish, all since the beginning. My corals are lots of mushrooms, zoos, one Xenia and on the top Acros, pink birdsnest, trumpet, plate and a brain coral.  All corals have a good separation. I feed the fish a large variety of frozen foods. The corals I feed a cocktail of Phycopure and Cyclop-eeze or DT's and for the larger coral I feed bits of fish food like Mysis. On Sunday I stir the top of the sand bed, clean my skimmer, 10% water change and run test. I have no algae problems, lots of coralline algae and everything is growing and happy.  In fact, at least once a month, I have to pull some of the corals and give them away. When I first got the Acros, they opened during the day for 2 weeks but for the past 4 months the Acros open only at night.  I see lots of them in other tanks that are open during the day.  I have tried to entice them with food during the day but it does not work.   <hmmm.. since they do not feed organically very well/heavily... this is not a principal influence (feeding). More likely water flow is the culprit. And the change from behaviors on arrival is simply their acclimation (or even suffrage if the flow is too low or way too high)> However, they eat well at night.  I have to believe that my Acros are getting all they need.  I know that I could use more light but they are at the same level as the birdsnest and if it is growing, I don't think that light is the problem. <agreed> Do you have any ideas? <lots... the Pittsburgh Steelers should try to run Jerome Bettis again this week and give Duce at least another week to rest> If you think it is the lights are VHO ok?   <very fine lights and good color. I like the URI brand best. Change any brand VHO by 10 months> MH just put out too much heat. <Ahhh... actually not my friend. It really is a misinformation. VHOs as close to the water as they need to be if effective (less than 3") are also hot. And either lamp style can easily be cooled with a single muffin fan (9 watts) and a well-designed fixture. MH are a better value by far in the long run considering lamp life, trueness of color, intensity (bang for your buck on light produced per watt), etc> PS I owe you all a big thanks.  I have saved a lot of money.  Fan vs. chiller in the summer, proper equipment selection, etc. Thanks <very welcome my friend. With kind regards. Anthony>

Lighting a nano for Acroporas - 11/23/04 Hey guys, I have a 10 gall nano reef tank and I'm running it with 8 watts per gal. (PC). Do you think I have enough light for Acroporas and clams. <Well, to be honest there is a lot more to lighting SPS and clams than watts per gallon, for sure. This is a much debated issue. First and foremost, you need a very stable marine environment. (unfortunately in my opinion, a 10 gallon is awfully hard to stabilize) Also, there is the debate regarding useful PAR from Power Compact lighting. I believe there are some PC bulbs out there that do produce useful PAR ranges for light loving Acropora and high light loving clams but I have yet to find any with long term success. I personally have not had a great amount of success with most SPS (Montipora capricornis and Hydnophora are one exception) but you might have some luck with some of the lower light loving clams like Derasa and Squamosa. I am not guaranteeing success but something that might work. Again stability, food, lighting, environment (i.e. water chemistry and flow dynamics) and water maintenance. A very had task but I do think it can and is being done. Do a little research and see what you can come with. Check www.nano-reef.com. Thanks for asking this important question here at WetWebMedia.Com. ~Paul> Thanks for your time Acro Question Hello. thanks for all the help keeping my reef in wonderful condition. Your expertise has been tremendous. I currently have run into what I think is possibly another small problem. I have an Acro which I got as a frag about 3-4 months ago. I attached it high up in my tank plenty of light and it seems to be doing quite well. It has definitely grown I see good polyp extension and all in all it looks fairly healthy. My concern is this. Imaging the Acro as a kind of an inverted tripod. At least the three main legs which have begun branching on their own but for our sake lets think that there are three main legs. The smallest of the legs which seems to have shown the least growth and looks the least healthy, has begun to over the last month slime over. The slime appears to be a white slime, fuzz, etc that is only on the tip of the one Acro branch. So if the branch was say 2 inches, the bottom inch and 3/4 is looking fine with polyps out etc while the top 1/4 inch seems to be covered in this white stuff. I can't blow it off with current at least not easily, a baster used for feeding etc, or rub it off with a light touch from my gloved hand. When I look close it almost looks like some of the white may actually be skeleton of the coral maybe it is dying as a result of the slime, maybe the slime is a result of death but it is really hard to tell as the very tip definitely looks soft and seems to be able to be blown off the coral although never completely. Is this normal? What can I do to reverse this trend, remove the white and get back my healthy frag? Should I cut off the branch? Can it spread to the other branches? It has been there for at least a month now and doesn't seem to be spreading although it looks like more quantity of slime has developed with time. Any help would be again greatly appreciated. -Jonathan >>>Hi Jonathan, My first concern would be current. Make sure you have plenty! It should not be linear, but as turbid as possible. Secondly, you may just be seeing an area of tissue loss due to injury. Algae soon colonizes an area such as this. In most cases, given proper conditions, it will get no worse. It does not sound like a case is necrosis to me. Good luck Jim<<< Branching Acropora resurrected...is this possible? Hi Bob, <Anthony Calfo in his stead> I have a most interesting phenomenon occurring in my 100 gallon reef tank.  On my last visit to a LFS the owner gave me an (apparently) dead piece of branching Acropora to use as decoration.  This fragment was sitting on a shelf and was completely bone dry.  It had probably been out of the water for several weeks. Anyway, I put the dead coral (bone white in color) in a niche among my live rock.  For about two weeks it still looked the same.  On the third week or so I started to notice that the coral was taking on a light red tinge.  Right now, after about 4 weeks, it looks almost exactly like one of the pictures on your site.  The whole thing has a light red tinge and the tips of the branches are a darker shade of red. Is it even possible for a dead coral to regenerate like this?   <Not likely after weeks out of water> The only other possible explanation that I can think of is that it is red algae growing on the dead coral.   <a much more likely scenario indeed> This seems unlikely to me, though, because I already have a bit of red slime algae growing on my overflow and it is a much darker shade of red.   <ahhh... there are many thousands of algae species this could be> I did have a problem with red slime algae a couple of months ago, but it completely cleared up except for the small area that I mentioned.  There is no new red algae growing anywhere else in the tank. <but there are the "seeds"/spores" of many not expressed but floating in the water pending optimal conditions or substrates to settle out from/on> My tank is not that old (only 5 months), but it is in great shape.  I have a deep sand bed and lots of live rock.  I have a venturi skimmer in a 20 gallon sump, but that is it.  The sand bed, live rock and skimmer have been maintaining the water with little to zero measurable ammonia, nitrite and nitrate.  I add calcium powder as necessary, trace elements about once a week, and phytoplankton about twice a week.  I have 2 VHO daylight bulbs and 2 VHO blue actinics.  The Acropora is sitting directly under the lights and gets fairly strong current. Thank you in advance for your wisdom on this phenomena. Whit Liggett <best regards, Anthony>

Lighting set-up question Hi WWM crew!! <Hi Steve MacL here with you today.> I wish to have shallow water species of invertebrate like Acropora. <Acroporas are a type of coral as I am sure you are aware, I get my words all messed up all the time as well. Gets me in trouble with the bosses!!! lol>  My tank is a 50 gal and is 18 inch deep. I am now lighting it with a 175w MH and I am thinking to add a 400W MH bulb. What do you think about it ? <A general rule is about five watts per gallon for the Acroporas.> ( do you think that my inhabitant would need some Coppertone?!) <You can always raise or lower both your lights and your inhabitant. Personally if I do it again I'm going powerful> Should I only add a 250W MH bulb ? I am thinking to add 1 or 2 actinic VHO to add some blue and to be able to make a dimming effect !! <Similar to the PFO lighting setups that are so popular!> Thank you very much for your answer!!! <Please let me know what you decide, MacL>

Acropora polyp extension 8/19/04 Hi, I'm getting sick and tired of my acros polyp extension. when I get an Acro that has long hairy polyps, a couple of weeks after I get them, the polyps are not hairy anymore, and shrink up inside the coral. What can I do? thanks, Adam <Hi Adam.  Adam here.  There are many reasons why this might be the case.  Please write back with some information about your lighting, water movement, filtration and water chemistry (Nitrate, pH, Calcium, Alkalinity).  Please also list the other fish and corals that you have.  Best Regards.  AdamC> <<Anthony here... as Adam C has stated... there are many possible reasons for this, and it is not even an indicator of good or better health. Still... if you want to finesse this, know that inadequate water flow (not enough or not enough of the right kind... as with powerheads/laminar outlets... yuck). Nutrient levels are an issue too... some folks cheat by adding a tablespoon of sugar to the tank on occasion. Not a great long term habit, but add one spoonful and see what happens (this is safe in one shot). It speaks to how some sugared supplements trick you into believing they are effective. Anthony>

Monti Eating Nudibranchs and predatory starfish I 8/11/04 Dear Bob Anthony, <cheers, my friend> First and foremost I wanted to say thank you for everything you do. I believe it can truly be said that this phenomenal hobby has advanced so much over the years because of your dedication to it! <thanks kindly... it is a labor of love> I had a quick question if you don't mind, and also wanted to bring to your attention an interesting experience that occurred. I am of the opinion that everything in the wild has its purpose, and will not try to eradicate anything unless it is truly harmful. <agreed... and yet, there is a joke somewhere in there about politicians. Well give lawyers a pass on this one> I have a fairly large system with 8 plating Montis in it. I went on vacation and when I returned I noted two plating Montis were suffering severe tissue loss. I thought the issue was more water quality related, particularly since my calc reactor had been down for several weeks and the filter socks needed cleaning. Despite water changes and dosing with Kalk, the affected Montis continued to RTN. I had heard of these little predatory Nudibranchs, but did not think there was a chance I had them. I fragged one of the Montis, and what do ya know there they were. Tons of them (to be honest, even though I have an obvious degree of hatred for them, they are fascinating). <Arghhh... you have not been diligent about quarantining your livestock my friend. 'Tis why you have this pest now. Do QT all things wet in the future - live food, live sand and rock, snails, corals, fishes, everything! <G>> My problem is the effected colony encrusted hardcore onto a large piece of rock, there is no way I can pry it lose. I am suspect that these suckers are concentrated under the base. Is there anyway to rid of these things? <they are very difficult indeed... do check the extensive threads on this topic at reef central. I cannot say the bad news any better than they have :p> Is there anything in the wild that eats them? <certainly.. but reef-safe? Hmmm... spec at this point. Some have said various wrasses and dragonets. None excel though reliably> I do have one CBB, but I would think some form of reef "safe" wrasse would be better. <perhaps... Tamarins or small yellow/green "Coris"> Also, wanted to mention in the past there was a dispute as to whether these little brown starfish we all have actually eat SPS (i.e. GARF). <Asterina species... and yes, I have read the GARF info. I do not believe it is accurate.> I had been in the SPS end of things and never had an issue so I was not concerned. Indeed they do eat SPS, the other colony I referred to above had tons of these brown starfish on the underside, right were the run line was on each plate. What is stranger, I have tons of acros and non have been affected. Looks like it is time to buy a harlequin (there are plenty of these things to last the harlequin quite a long time).  As always thanks!!!!!!!! <do check out my take on Asterina and other sea stars in the recent article on reefkeeping.com from a couple of months ago. Best regards, Anthony Calfo>

Monti Eating Nudibranchs and predatory starfish II 8/11/04 By the way, I am curious (from a scientific perspective) as to whether these predatory nudi's show a preference for certain species of plating Monti, or whether this is just a random event. <there are quite a few opisthobranchs that are obligate on one species of invertebrate or very limited (by genus usually) otherwise. There are lists of slug species and their prey available on the web. DO check out resources like the seaslug forum. We also have an extensive list of web sites and references on seaslugs in the bibliography of our book "Reef Invertebrates" by Calfo and Fenner 2003> What I think is strange is the nudi's have only affected one colony, none of the others have them (at least not yet). It would be neat to take frags of say 10 types of plating Monti, and see which species they show a statistically significant preference for Thanks <please do take photos and tell us of your findings if not write an article. Anthony>

Red bugs on SPS hi, Bob, how's going? << Blundell here as well. >> This is George in SDMAS. << Hey George, hope all is well. >>  Got a question for you about red bugs.  I am sure you probably read some posts online about it.   Some ppl use a heart worm medication call "interceptor" to get rid of the red bug.  Supposedly the only side effect known at this point is that the medication kills most if not all the crustaceans and everything else seems to do fine. << Wow, I wouldn't call that all successful.  If it kills all the other crustaceans then I would stay clear of that method. >> Someone also said that pipe fish eats the red bugs. So I decided to do an experiment.  I have Ron got me some dragon pipe fish. I put them in my refugium/frag tank.  Saturday they feel comfortable enough, the male start to compete against each other to see who is most handsome and the female pipe fish just doing whatever they are doing like nothing is going on.  So I dropped a SPS colony that has red bugs on it in the refugium/frag tank.  So far I only observe 2 pipe fish swim onto the colony look around for food, but some how they didn't eat any of the bugs. SO they either don't realize those bugs are food, or perhaps not that hungry, or some how they can't see them.  Since pipe fish aren't build for living in rough water, so I am more leaning toward they don't know what the red bugs are. <Me too> << Definite possibility.  But with time, and hunger, they may go for it.  Or, is possible that the red bugs aren't food at all for them. >> I am planning on feeding the pipe fish some Cyclops eeze tonight by squirt some into the SPS colony, hopping maybe the pipe fish will eventually associate the bug and food together.  But of course they have to start eating the Cyclops eeze first. << Good idea, and just about everything will go for Cyclop-eeze. >> My question is that from all your dives and observations when you were diving.  Do you know if any fish/shrimp/crab....etc that live in the reef that might eat these red bugs?? <I don't, but suspect there is definitely some predator/s> <<  I would think a wrasse would be the best choice.  Probably trying a rock mover (dragon wrasse) or six line wrasse. >> If you do, I would appreciate if you let me know.  I am sure I can spend money and try all the reef safe fish that I think might eat things like red bug, but don't have that kind money to throw around. << I wouldn't spend any money on chemical treatments.  I would stick with fish (wrasse) or maybe even a Mithrax crab. >> Hope to hear from you soon.  Have a great day! Sincerely, George <Hey George. Am sending your note/query to our Crew... as they are much more current on this issue. Be seeing you, Bob F> <<  Blundell  >> Alkalinity drop 7/23/04 I had been using Rowaphos for a few months with no problems. Unfortunately while on vacation, my Calcium Reactor output hose clogged up and the alkalinity dropped from around 10 to 6 ! This severely stressed out several of my favorite colonies including: Tri-Color Acro - this is the worst one hit but there are some live branches with many polyps under the dead white tips. Hydnophora - looks like this may recover from the bleaching Baby Blue Acro Frags- have many of these so not a biggy Blue Acro tortuosa - Tips are turning white, not sure if it will make it. One of my more expensive and most favorite pieces. <I am not convinced that a drop in alk to 6 would be enough by itself to cause this.  How sure are you that nothing died while you were away, causing an ammonia spike and how sure are you that your temperature did not rise more than about 4-6 degrees above normal?> My questions are:  What is the difference between bleaching and RTN ? My colonies did not all die in a matter of hours, but instead are bleaching slowly....although now that I have stabilized the water parameters (Ca = 430, Alk = 10) the bleaching has slowed but still continues. <Bleaching is the expulsion of zooxanthellae.  RTN is a condition where the coral "self destructs" and the animal itself dies and the tissue sloughs off of the skeleton.  I agree with your move to correct the alkalinity, and recommend carefully monitoring temperature, alkalinity, pH and other parameters and focus on STABILITY!  I would not try to aggressively correct any other parameter unless it is dangerous (ammonia?).> Should I remove the affected colonies ? <I would not.  Moving them would be another undue stress.> Should I frag the affected colonies to save what I can, or leave them alone and hope they recover ? <I would leave them alone.> Thanks in advance for any help you can offer. <In the mean time, I would recommend lowering your light levels a bit.  I would do this by reducing intensity first (fewer lamps running, raising lamps higher above tank) and only shorten the photoperiod if you don't have any other choice.  After a week or so, work your lighting back to normal over a week or so.  Best of luck!  Adam> Calcium Reactor Not Required?   <Hey there, Scott F. here with you tonight.> I have a 400 watt 10k bulb on with a spider reflector, metal halide lighting setup. My question is how can I keep Acropora hard corals in it without a calcium reactor? <How?  By regular additions of calcium in the form of Kalkwasser or two part Calcium\Alkalinity additives such as B-Ionic, or C-Balance, etc.  Yes, a calcium reactor is more convenient with some respects but wonderful reef systems can be maintained with calcium supplementation as outlined above.> If so, what can I start out with that's not too demanding as far as Acropora goes? Are there any easy SPS that will thrive under these conditions? <There are many species that will fill the bill.  I highly advise that you purchase a good coral reference such as Eric Borneman's "Aquarium Corals" or Anthony Calfo's "Book of Coral Propagation.> I just want clams and SPS corals. Can I get away without purchasing a calcium reactor? <Sure, as I already mentioned above.> In dire need, Carlos, in Salinas, California. <Good luck Carlos, and happy reefing!  Regards, Scott F.>

Acropora keeping sans calcium reactors? hi I e-mailed you guys yesterday and I got no response? << Sorry, we get lots of emails which are shared by lots of people here. >>   I was asking if its possible to keep Acropora species alive and thriving without a calcium reactor? << Absolutely.  Most people don't have calcium reactors. >>  if so what kind and what species will make it? << I don't think calcium reactors are at all necessary.  Convenient yes, but not necessary.  I would think you are okay using two part additives like B-Ionic. >> thanks in advance, Carlos, from Salinas, California.  << Adam B. >>

Heavily sliming Acropora 5/3/04 Hi, could you please tell me which Acropora species slime the most heavily? Thanks <Yup.  The slimiest one!  Seriously though...  Many Acroporas are copious slimers.  The problem is that despite the fact that so many folks attach species names to their Acroporas, making such an identification is nearly impossible for the average (even advanced) hobbyist.  Comparison to a picture in a book doesn't work.  Even a very detailed analysis of the gross physical characteristics of an Acropora will usually only narrow down the choices.  In many cases, microscopic examination is required.  Sorry for the rant, but as you can tell, this is a pet peeve.  Best Regards, Adam>

Yellow with a red dot Acro bugs 5/3/04 Hi, I have some Acropora corals that are infested with little yellow oval shaped bug like things on them. I am afraid that they are hurting or eating the Acropora corals. How can I get rid of them? I have a yellow Coris wrasse and a mandarin fish but they are not eating the bugs. If I use SeaChem's coral dip, will it kill these pests? Thanks, Adam <Hi Adam.  Adam here<g>.  There is much debate about these critters and why they appear, what they feed on, if they are harmful, how to get rid of them, etc., etc.  Some folks have had success with predators, commensal crabs or clown gobies, but none are 100% reliable.  I never like to send anyone elsewhere for info, but I don't have any first hand experience and there is A LOT of discussion in the forums at www.reefcentral.com.  Good luck!  Adam>

Acropora fragging and aggression - 4/5/04  Hi, what would happen if two of my Acropora corals touched each other? <Sometimes they grow together, other times they kill of the area where they are touching. Do search for SPS aggression on Google. There is much info available on this subject> Also, is there a minimum size an Acropora coral frag has to be? <Not really. I have tried 1/2 inch on up. Sometimes they make it, but there is usually high mortality in very small frags (under an inch)> Thanks, Adam

Tissue Necrosis on Acropora 3/28/04 The bottom of this Acro seems to be dying and slowly moving up. The dead area you see in the picture took about 10 days to get that high. It's about 1/2 inch by 1-1/2". I've included a picture of it while it was healthy also. What is it and how do I fix it?? Thanks in advance - Chris in Georgia <there are numerous possible reasons and few if any clear answers to why tissue necrosis occurs in SPS corals. Without a speck of information on your system, I cannot speak to the possibilities. Please do use the terms "tissue necrosis Acropora SPS" and various combinations in a keyword search of our site and beyond. Also, do read Eric Borneman's excellent coverage of coral pathology n his book "Aquarium Corals". Kindly, Anthony>

Acro Suffering Algae Hello Folks- <howdy> I have a beautiful Acro that has a brown film algae develop on the tips. At first I thought nothing of it but it has now spread from on or two tips to about 6 or 7 . It seems to be only on the tips and spread to a few corallites near the tips and not down the whole stalk. I moved the coral away from any direct current but that has not helped. I am worried that it may be the beginning of the end for one of my favorite pieces. (tried water changes)....Any ideas ? Is this a common occurrence ?. (BTW no other acros in the tank have any problems including the frags of this colony) Dan <without a picture of better description, I'm not much help here. For a diatom or other brown algae growth to be encroaching live tissue, you would/should be reporting receding flesh/tissue of the Acropora. In such cases, the tissue is sometimes even long since denuded and its the corallum that is being settled. If this coral had direct laminar flow before, that may have been the problem (unnatural water flow which pummeled healthy flesh into giving way to brown algae). Do send clear full-frame picture if you can. Thanks kindly, Anthony>

Acro Suffering Algae II 3/1/04 Thanks Anthony, I have attached two pictures. I have yet to master this (**^$^% digital camera. <Hmmm... yes, helpful. The color and apparent texture of the algae remind me of a dinoflagellate infection instead of a diatom algae. Do check you pH and Alkalinity. Dinos like this often show up when the aforementioned are flat (under 9dKH and under 8.3 respectively). Aggressive protein skimming and daily use of Kalkwasser alone can eradicate this pest. DO let us know if it helps! Anthony>

Acropora millepora growth hello guys, <Hello - An "SPS freak" at your service :) > I have an A. millepora that's been in my tank about 3 months now.  happily, it has been growing like crazy, and the new growth is a very nice purple color with teal polyps.   <Sounds nice.> here's the thing... in my experience these colonies grow in a pretty random upward and outward branching fashion.  the branches on this one, however, started out pointing upwards but have now all bent outwards and are growing laterally and branching very little.  the result is a pretty odd looking colony.  I am trying to think of a reason the colony would want to expand laterally and not upwards, towards the light... could it be that it is in search of more intense light?  (I have 175 10k's with PC actinics)  I am curious to hear your opinion on this. <Well, Mario, most likely this growth has to do with the current it's receiving. Generally speaking, the more current you give a coral the compact the branches will grow. It's interesting point out that many A. millepora specimens in the wild have a table growth form, so this growth your observing is quite normal. As long as it seems to be growing, I wouldn't be worried about it at all.> thanks, <Take Care, Graham.> -Mario

Something eating SPS - Montipora Anthony, happy holidays and hope all is well with you. <Adam here today.  Anthony bumped this over to me since I just dealt with this problem in my own tank.> I noticed one of my recent frags, a Montipora's Cap,  that is purple in color bleached around the edges about a quarter of an inch.  This is more then the  normal white tips from growth.  I attributed this to a drop in Alk while I was adjusting to my winter evaporation rate.   <I did pretty much the same thing.  I attributed it to water quality, did some water changes and never really inspected the coral closely.> However, I have noticed a small white spiral looking thing on the white part of the coral.  Looks almost like a very small white fan worm (at least the ends of the fan worm anyway). <The critter you saw is an Aeolid nudibranch.  They seem to becoming quite common in the hobby, likely from frag trading.  They seem to favor plating Montiporas, but will move on to branching forms.> I also noticed a small white area on my established, thriving purple cap.  Could this be a bug or something?  Any ideas or am I  just seeing things. <The white spots are where the nudi.s have eaten the coenosteum (tissue between polyps) of the coral.  Unfortunately these are very real and quite difficult to get rid of.  Manual removal is the only way to do so without significant risk of killing the coral.  You will have to remove the infested corals every day or couple of days and pick or scrub off any nudibranchs or eggs.  It may be best to this in a bucket of tank water since the critters tend to collapse under their own weight and become difficult to spot out of the water.  After you are 100% sure you have eliminated them, continue to check your Montiporas at least weekly.  I continued to find one or two a week for about a month.> Thanks <No Sweat, and best of luck!  Adam> Andrew

Mini Garden Reef Hello, <cheers> I bought a Purple Acropora w/ Green Polyps for my 7 gallon minibow.  Do you think the CSL SmartLite-Retrofit 32 watt http://www.premiumaquatics.com/Merchant2/merchant.mv?Screen=PROD&Store_Code =PA&Product_Code=CSL-SLRF32&Category_Code=CSLr) will provide it with enough light? <seems possible> If it happens to not do well, will there be adverse consequences in my tank? <hard to say... but likely not short of an infectious disease that blossoms from necrotic tissue. Instability is inherent with a tank this small> I house some zoos, xenia, clam, candy cane coral, small tulip anemone, goby, etc. <yikes! The hodge-podge mix of unnatural tank mates in such a small aquarium seems like a bad idea to me in the long term. I cannot imagine the water changes and fragging that will be necessary to pull this off successfully in the long term. Do try to be more specific with stock by group/family> Thank you very much, Anthony  Here is a picture of it: <best regards, Anthony>

Acropora polyp extension 3/3/03 Hi Gang, <cheers, bud> I have a question regarding my Acropora.  I have three different species, some I've had for over three years.  My most recent are the more thicker stem species that look like the Aspera or Tenuis species.  The latest is a really nice tri-color from Walt Smith.  The problem I am looking for help on is the polyps are not extending.  In the store I purchased them from they appear almost fuzzy like due to the polyps.  Mine are smoother due to the retraction.   <the list of possible influences is daunting... in contrast to your dealer's display: water clarity, age of lamps, color of lamps, direct and total energy of water flow, DOC levels... etc> The growth rate is good, but I fear that this may not be for long.   <polyp extension is not correlative to growth rates, bud> My tank parameters are good. T=75, DKH 10, Calcium a little low 360 (no reactor), Magnesium 1350, <easy on the Mag with a lower Ca> and ORP 345.  I change about 10 gallons a week in a 125G tank with 35 gallon refugium on reverse lighting with sea grasses no Caulerpa.  main tank lighting is 3-175 watt MH, and 2 VHO 140 Actinic.  I also have 2-tangs 6", and 5 small fish 3".  I have never seen any fish peck at these corals.  Any ideas??   <the most common and easiest parameter to tweak is water flow... usually more is better. Adjust or increase the amount this coral gets... avoid laminar, of course. The other thing is that LFS waters tend to be higher in DOC levels, lower in water clarity and light (age of bulbs, salt creep, etc) due to commercial "business" and setting... all of which may force a coral to extend polyps further panning for light and food. It not always a good thing. Extension is good... overextension is bad. Ciao, bub. Anthony>

Montipora digitata 3/3/03 Dear Bob and crew, Guess what!, I've finally found the Anthias that would stay alive in my system! <wow, that's...er, great. Hmmm... if ten die for every one that survives import, and five died before you ... er, never mind. Glad to hear that there's a spark of life in the Onion field> I picked up a 2 inch fathead Anthias and its striving well in my tank, eating heartily and swimming around the tank in open view most of the time. <indeed an excellent species and gorgeous.> I'd like to add an argi angel to my tank but would be afraid that it may pester the Anthias even though it seems to be able to hold its hold in my tank chasing off the royal Gramma and the 2 inch Kole tang....any comments...the argi is not necessary....it was just an after thought to help with some micro algae. <no dwarf angel can eat anywhere near the algae as your wonderful Kole tang, and the C. argi is one of the riskiest coral nibblers among the dwarf angels. I'd pass> On to my real question. I picked up an okay looking brown Montipora digitata specimen which has about 5 sticks going across from left to right. It had a little bit of receding to it when I first got it and I was hoping it would come to a stop. I placed it really high up in my tank, approx 1 inch away from the surface of the water where it could get max lighting. However, it is directly placed next to an individual disc mushroom that is of a pretty good size....I know there is chemical warfare going on here <not a matter of could... it is severe. Corallimorphs are top ten on any list for potency. They don't have to touch... even 6" away is not enough by some measures (6-10" is standard distance for most corals in place to allow for growth and minimize even shed compounds)> but could that be the primary reason this coral has continue to recede..... <almost certainly... Montipora is one of the weakest corals and the 'shroom is one of the worst. Other reasons here too perhaps> little by little from the base upwards, it has started to bleach. Surprisingly, its the sticks that are farthest from the mushroom that are receding.....2 of them.....the rest of the three sticks on the left hand side are doing quite well....polyping out all the time and even starting to grow pinkish purple tips. Should I break off those two sticks on the right hand side to avoid contaminating the left 3 sticks or should I move this specimen of Montipora? or both? <indeed... both please> Any advise would be appreciated! <the best advise I can give you is not mix unnatural groups of coral... especially in a smaller tank. Pick one group (shrooms, SPS, or LPS, etc) and stick with it> To refresh your memory, this is a 40 gallon tank, 16in deep...0 nitrite, 0 ammonia, 0-10 nitrate, Tank is actually rather poorly lit due to only 4 watts per gallon of power compacts 50/50 bulbs which is why I placed the Monti so high up. <understood and agreed> Is it from insufficient lighting? <yes> Should I just stay away from SPS altogether due to the lighting issue? <certainly... this is even modest light for hardy Montipora> I just thought I should try it out because I have researched and the digitata seems to be the hardiest of the SPS and I actually don't mind it being brown in color. <agreed> I fell in love with the SPS after a recent Christmas trip to Thailand and snorkeling in the Similan Islands....have you ever been? <nope... but Bob likely has> Its magnificent! Hope to hear from you soon. Sincerely, jimmy <kindly, Anthony>

Bleached coral- how to handle We have a 20 gallon reef tank in our home. Recently we have been given an Acropora. However it is white with blue/purplish tips. <ahhh... bleached with only U.V reflecting pigments left. This coral will die within a year if it is not fed and colors up (likely brown... hopefully... with purple tips> I have read about them and understand that there is no naturally white Acropora. <exactly correct> I came across a post on your website that described a similar Acropora. The Acropora we have although white is loaded with green polyps. What is your opinion on this Acropora? The coral is indeed bleached and the pigments you are looking at are reflective proteins and not zooxanthellae> Would the polyps still be open and thriving if the Acropora was bleached? <absolutely...one thing has nothing to do with the other (feeding organismally on nanoplankton versus symbiosis. What you need to do is fed this coral... but because the polyps are so small (and your mention of a 20 gall display leads me to believe that you do not have a plankton generating refugium), there is likely little hope for this coral to survive here. If you do not choose to move the coral to another tank, however... my advice is to make sure that you have a source of nitrogen in the tank (allow nitrates to linger). If your nitrates are low, you can make an ammonium or nitrate solution to dose the tank with (carefully) to feed the coral. Also, know that this coral will not eat bottled green phytoplankton. It needs zooplankton so small that you cannot provide it from a bottle or can. Do consider adding an upstream refugium to your tank (no Caulerpa though). Gracilaria or Chaetomorpha will help you to grow nutritious plankters for your corals below> Thanks for your time and help. Sincerely, Tana Landau <best regards, Anthony>

Acropora and Sea Fan questions Hi all!  Thanks as always for a great site.   <our pleasure> I don't know where I'd be without my daily dose of WWM. <out of the Institution, perhaps?> My first question is really more just curiosity than a problem (I hope). I've noticed that my Acropora polyps are almost always out during the day.  They close after the lights have been out for a while or after a feeding. <feeding particulates that is... they prefer nanoplankton and feeding by absorption instead (some). Thus... no need or irritation by the turbidly of plankton at night or your feeding> I'm puzzled because the Acroporas that I've see in the display tanks at my local pet stores are always closed.   <varies by species, water quality, water flow, etc> The pictures I've seen are usually too small to distinguish the polyps.  What is the normal behavior supposed to be?   <varies> Do I have anything to worry about?   <nope> I've attached a picture so that you can see what my coral typically looks like.   <a handsome coral> I hope it's not too big, <if only I had a dollar for every time I had to say that [fill in your own joke here]> was the smallest I could make it without losing the detail. <[follow up joke inserted HERE]> I feed them a variety of meaty foods that I blend in a hand-held blender until very fine.   <a nice effort but likely little help. They do not eat phyto... and prepared meaty foods are grossly too large. They need nano-sized zooplankton. A fishless upstream refugium would be a much bigger help> I feed the tiny suspended food to my small polyped corals and sea fan, <yes... better for the sea fan indeed> and the larger crumbs that settle on the bottom of the bowl I feed to my sun coral. <good strategy> My sun coral, by the way, is doing very well and growing fast. <excellent. Do look in archives for the old article in Aquarium Frontiers by Joe Yaiullo on asexual planulation of this coral. Fantastic!> My second question is about my sea fan.  There is some Cyanobacteria growing on the fan -- but no where else in the tank, <yes... needs more random turbulent flow here... they have evolved by design to trap particles!> fortunately.  How can I safely remove it?   <just better flow bud... tweak your outlets but no laminar action here. Have two effluents converge above it perhaps> The Cyano is beginning to smother the fan, but otherwise the fan seems to be doing very well, even growing.  I've included a picture of the fan.  You can see the dark areas where the Cyano is growing. I have a 75 gallon tank with lots of live rock and about 3 inches of live sand.  I keep a protein skimmer and a small carbon filter running all of the time.  My protein skimmer is a Turboflotor 1000 multi.  The cup is filled about once a week (is that enough?).   <not really... (hence the Cyano). This is a skimmer with a good design that needs pampering and tweaking. There are even companies that sell modified Turboflotors. Browse the archives here and the message boards for modification tips and tricks.> For lighting, I have a 384 watt PC with two 10000K and two actinic bulbs. My water parameters are: >pH = 8.3 >dKH = 9.3 >Calcium = ~400 >Ammonia = 0 >Nitrite = 0 >Nitrate = 10 Thanks, Patrick <best regards, Anthony>

Acropora injury Hi! I have 440watts of PC lighting and  a beautiful piece of purple >Acorpora(5x4 inches in size) which is from my local fish store Purchased 2 months ago)- It has about 8 different large branches coming off it.  It did fine for the first 6 weeks. It still is doing fine but 2 weeks ago one of the branches started to turn white at the very tip of the branch. This particular branch is about two inches tall. For about a week, the whiteness worked its way down the branch. I became very worried the whole coral was going to di. But now it looks like the whiteness/it stopped progressing>down the branch. For over a week  it hasn't become worse. It only worked its way down about 1/4 inch of the 2 inch branch. The whiteness has now turned brown. <it is difficult to diagnose without seeing it or a photo, but it sounds like tissue became infected and denuded. The white corallum (skeleton) was exposed and has now been attacked by diatoms. The coral may reclaim or lose tissue. Hard to say. Do you really have the tank for SPS corals? Very stable Alk, Magnesium and Calcium? You test for these things regularly and dose daily? What have your parameters been specifically?> Are my worries over?   <I suspect this is a mixed garden tank too... mushroom anemones, LPS corals, soft corals. Going to be challenging to keep the SPS more than 1 year here> If not, What can I do to help this coral? I do have other Acroporas for over 4 months that had no problems- Should I consider cutting this tip off and allow the branch to grow back? <Definitely break this branch off... if is easier to regrow a branch than reclaim one with diatom algae> Please let me know.- Thanks Ron <you may want/need some more information before proceeding too much further with delicate SPS corals. I get the vibe that you are very new to at least this aspect of reefkeeping. Live animals here... not stereos or widgets. Perhaps you should get (or read) a good book too before buying another coral my friend. Let me suggest Eric Borneman's "Aquarium Corals". Covers corals diseases at great length too. Best regards, Anthony>

Micro-Acropora Reef Possibilities? Hey Everybody, :) <Hello!> I've been toying around with the idea of setting up a micro-reef in a spare 5.5 gallon tank I've had laying around for awhile.  I had a very successful set up for about a year with a 5.5 gallon tank housing a single blue damsel, a Firefish dart goby, some mushrooms and a bunch of Halimeda that I harvested regularly for nutrient export.  I was surprised at the diversity in such a small system, in the likes of sponges, worms, amphipods, snails, small brittle stars, etc.  I eventually tore the system down and moved the Firefish to my main 75 gallon mixed reef and sold the damsel back to the LFS.  The tank has been laying idle for awhile (after a brief stint as a freshwater fancy tailed guppy tank on my desk) and I have decided to finally try another micro-reef.  My LFS has a small compact fluorescent fixture for 5.5 gallon hoods that is 10 watts at 6500K (comparable to 30 or something like that in incandescent lighting) which I was thinking about getting two of.  I would use a fairly thick 3 maybe 4 inches of sugar sized aragonite sand, with some live rock to cycle it.  Adding a small power head or two aimed at the front glass panel for random diffused currents and possibly a small skimmer/filter contraption or something else for additional filtration.  I was wondering if it would be possible to house a few small frags of Acropora in the tank.  I know they are very difficult to house and I was wondering what your input would be on this idea.  What problems would you foresee?   <I guess I don't need to preach to you about the difficulties of micro marine tanks. I even had trouble with a 5 gallon freshwater tank! I can only speak for myself on this one...but this would be a difficult challenge. All of the problems inherent with keeping Acro in large tanks will be magnified...everything from water chemistry to salinity to temperature, alk, calcium, etc., will be compounded in a tank this small. Large reef tanks can crash fairly easily if good husbandry is not followed daily/weekly. In a 5.5 gallon tank?...I don't even want to think about what could happen while you are on a 1 or two week vacation...>   What variations to my plan would you suggest?   <Honestly? A larger tank...> Any advice from the experts would be very welcome.   <I'm not an expert on acros...But I do see a lot of difficulties with a micro system that holds delicate corals like acros. This will be much different than the Halimeda, mushrooms, etc. that you kept in the old tank> Thank you guys so much in advance and keep up with the excellent work.  :) <Thanks my friend! I invite you to not necessarily accept my opinion but research through other literature/websites and decide if this is a gamble that you want to take. You're going to be climbing a tall mountain...> Sincerely, Dan <Best of luck! David Dowless>

Nano Reef Hey David :) <Hello again!> Thanks for your honest reply.  It seems you're echoing the same thoughts going through my head about the problem of tank size.  What do you think the minimum set-up would be to keep a relatively small tank stocked with some Acropora frags?   <My friend...anything will be an improvement over 5.5 gallons> I have a small terrarium (false bottom set up with small power head forcing water from the dead space below into a piece of cork tube that looks like a tree and some moss and a few small tropical plants) on one side of my desk and would like to put a small comparable in proportion saltwater tank on the other side.  A 5.5 gallon would fit perfectly on the right and match the terrarium in size, but like you mentioned, the size is one of the greatest problems in and of itself.  I was just wondering what your thoughts might be on the minimum size should use.   <Well...A 10 gallon tank would be twice as large as a 5.5 gallon...Geez...That's really a small, small, minimum> Oh, and my terrarium was a freshwater tank for three years before I converted it this past summer.  It housed a Betta, some feeder guppies I allowed to reproduce to feed the Betta, some freshwater mussels I harvested locally from a river, for a short while a blue crayfish (until he was moved to his own tank a few months later and ultimately traded back to the LFS), and a LOT of Java moss.  That stuff grows so fast that it does an excellent job of nutrient uptake and eventual removal, just like a refugium on a salt tank.  And, you can trade it in at the LFS for some credit towards other gadgets and critters, usually.   <I've had that experience with Caulerpa and Halimeda. It is nice> :)  The best part of the tank was the Java moss itself, since when left nearly undisturbed for a good while between harvests, it formed what looked like fern covered hills in the tank with such a small scale.  That, coupled with the fish swimming around them, it was quite a sight.   <I'll better it was... Sounds great!> Anyway, a small freshwater tank has proven to be very easy as long as I use plenty of Java moss, and a small normal saltwater tank was also fairly easy as long as I kept plenty of Halimeda.  So, perhaps I should try another form of nutrient export if I give this venture a go.   <Hmmmmm...It seems that you are planning to fit a particular area on a desk...with dimensions that fit the 5.5 g? That's what makes this hard. If you had room, I would suggest buying a long tank that isn't very deep...Then you wouldn't need really strong lights. Tank depth is a lot of what sucks the life out of lights. A 10 gallon would be better than a 5.5 but...I've had experiences with 10 gallon quarantine tanks...They're still too small for me...Water chemistry, temperature, ammonia, nitrite, and top-off just change too fast. Okay...I'm going in circles here. A 10 is more stable than a 5.5, a 20 is even more stable, 55 even better. Let me hasten to add that since you seem to know what you're getting into...maybe with a lot of diligence, a 5.5 might work...Who knows? Many people that try these things don't know the odds they are up against and that is their main problem. What you are proposing won't be easy. You'll notice that I didn't say it was impossible. Success in this hobby is determined when critters live for years and that is hopefully your goal. At some point you will need a bigger tank if everything survives and thrives long term>   Any ways, I'd best be going now and I hope you have better luck next time with a smaller freshwater tank and let me know what you think about the size of the tank for the acros.  :) <Thanks for the encouragement! Believe me...I have a 100 gallon reef and it's just about all the work I can handle...HA!> Thanks again, <You're most welcome! David Dowless> Dan

Acropora Confusion I have two small fragments of Acropora that I got from two different places. The polyps of the two fragments are very different, so I was wondering if they were both really Acropora.   <It is difficult to tell. Skeletal features may give clues as to the true identity. Growth patterns are imprecise at best. There are many growth forms of Acropora from branching, bushy, cluster, finger, etc.> The first one I got has brown polyps that are about 1/4" in diameter.  The second one I got has green polyps that are barely visible.  What's the best way to determine which species I have?   <Impossible for me to do over the internet although photos would help. Get a copy of Borneman's book "Aquarium corals: Selection, Husbandry, and Natural History. This book contains lots of pictures and identifying characteristics. No book will have every known form of a coral, but this book does contain information on many commonly kept species of corals> Is it possible that the brown polyps will change color with time (and the right environment)? <Your brown Acropora is likely from lower light level and lower water movement. It is possible for an Acropora to modify its color (zooxanthellae) due to the effects of lighting> Thanks. <You're welcome! David Dowless>

Acropora emergency I can't stand it.  I just can't stand it.  <sigh> You've been helping me with some lighting issues, which I really appreciate, but I'm starting to think it's not the lighting.  My biggest problem is that I can no longer seem to keep Acropora alive. <so many possibilities> I had two pieces for a couple of months before a water circulation problem (blown pump) killed them.  I had acclimated them, and they seemed otherwise healthy, so I replaced them with another piece, but stupidly didn't acclimate.  It bleached within a week.  OK, I thought, my fault, and for the replacement to the replacement, I've gone the whole nine yards, with the screen method, to acclimate.  Everything's been fine for a week...and today I get up to find the bases of several of the branches are bleaching. I've checked most of what I can think to check: am,>ni, nitrate all zero; Ca at 500; <lets stop here. We may have a water quality issue. Either your Ca test is inaccurate (500ppm Ca is dangerously high if even possible in most tanks without a precipitation of Alkalinity)... Or... your alkalinity is on the floor! I can almost guarantee you that if you test your Alkalinity/hardness that you are well under 10dKH. Quite frankly... I won't be surprised if you are under 6dKH! Very dangerous and could easily foul Acropora and other SPS. Target 8-12 dKH and 350-425ppm Ca but not the high en of both simultaneously. Use a LFS or another test to compare your kit's accuracy of a water test> with a chiller, the temp stays at 78 24x7.  If you recall, I had 20K 250W>MH lights when I got the piece, but switched to 10K for a couple days due to other issues; I've put the 20K bulbs back, but with the heavy screen it's had, I didn't think that would cause the piece to start bleaching, especially literally overnight - I looked at it last night, it was not bleached at all (believe me, I've been checking 5 times a day).  I have noticed that the polyps never really have extended, but I thought it was due to the move and have been waiting it out. <the switch was indeed stressful... but I am wondering if this isn't really a problem with skewed Ca/Alk dynamics or consistency> Is there anything I can do to save this piece?   <we need to ID the cause before we can say whether to pull the coral or not> I'm sick of watching Acropora bleach.  Other corals (mostly LPS and soft) all seem fine - <more tolerant> including a large branching Hydnophora excesa (I believe - it's a fuzzy-looking green branching SPS), which has done fine from the beginning. <it is one of the worlds hardiest corals... I have seen them propagated by literally running them through a band saw!!!> Any ideas?  Or am I just going to remain an Acropora killer?  Arthur <no worries... we will figure it out in due time. Anthony>

Re: Acropora Emergency An update; I performed a few moderate water changes over the last two days, and have swapped out the equivalent of 60% of the original water.  The new reading for Ca shows around 420, but I'll let it settle for a day before reading it again.  Alk is still 11.  Things seem a little "perkier", but they always do after a water change - probably a good indication that my skimmer just wasn't cutting it. The Acropora emergency is over - it's bleached over 75% of the piece, so I expect it'll croak.  RTN stinks.  I'll go back to daily Ca checks for a while until I get some stability. <Sounds fine now, sorry about the Acro. Test calcium and alk and then let it run for four days with no supplements. Test again and divide difference by four. That is what you should dose of calc  and alk supplements daily.  11 alk and 420 calcium is just on the high end of optimum for both. They could both come down a little with no problem.> I've already purchased the Remora Pro (today), so at this point, over the last 2 months, I've replaced or added: the chiller (1/4 HP), canister filter (Hagen 404) leading into a UV sterilizer (CSL double helix, to help fight ich - won't be permanently on), lighting (from 4x110W VHO to MH), and now the protein skimmer (Remora Pro).  The last thing I'm going to do is convert the sump to a refugium (when I can remove the in-sump skimmer I have and get the room back).  For a 75 gallon tank, I have to believe this is getting close to optimum conditions- I suppose I could always add a Ca Reactor, but that isn't going to happen soon (not if I want to stay married :)).  If I can't get some stability now, I really *will* consider changing to guppies...:) Thanks for the help... Arthur <Hmmm, sounds like my house.... Do have fun!  Craig>

Acropora "mites" AKA 'Red Amphipods" I have a 10 gallon nano with some small SPS frags and I have notices small orange mites crawling around on a couple of the Acropora frags.  <ahhh, yes... not uncommon at all. A curious little arthropod. AKA "red Amphipods"> They look like little fleas. They are very small but viewable to the naked eye. What can be done?  <some say they are parasitic, but I and most aquarists do not believe this to be true. No proof yet. At best they flourish incidentally while SPS corals wane/die from other common denominators (water quality, lack of QT, etc)> Is there a safe dip or treatment I could give?  <some have employed FW dips... I do not believe this is necessary> Are these parasitic or commensal?  <the jury is still out... leaning towards commensal> I have searched and found no information on these.  <do a keyword search on reefcentral.com and other large message boards for perspective (use "Red Acropora Mites", "Red Amphipods", etc.) to get a consensus. My advice is to simply watch carefully and do employ a natural predator if possible (Red Sea pseudochromid, small wrasse, etc)> Thank you ahead of time for any help. <best regards, Anthony>

Acropora Tissue Recession Hey Crew! <whassup?!?> I am not sure what to do with my staghorn Acropora.  <grow it, frag it, trade it... get more Acroporas> Its about 5in diameter purple branching and showing steady growth from the axial corallites. Everything seems normal however there is very slow tissue recession at the base.  <a common symptom... many reasons for this... inadequate water flow, static posterior lights (as from focused pendant halides instead of nicely reflected horizontal mount bulbs or bulbs on tracks), disease (rare)>  There appears not to be any peeling of tissue at all; just seems like every week when I look at the white band at its base its getting wider. I guess its losing about an 1/8 inch weekly. Odd to me because I have had the "Rapid" variety before and it definitely is not showing this. Furthermore I have purchased other Acropora on the net that looks to have some old recession that has since been grown over with new tissue on top of the dead parts.  <good to hear... but please be sure to QT all new animals... fishes, corals, crustaceans, mollusks...ALL! 2-4 weeks minimum to reduce risk of transmitting disease> When I originally received this internet bought Acropora I thought they ripped me off by sending me a Trojan horse to destroy the rest of my corals, but after close observation, the recessed parts are not expanding and is showing good polyp extension.  <at any rate... Trojan horses only work if you let them into the castle, right? Please always quarantine all livestock, my friend. It is proper and responsible if not respectful to the living treasures we keep> Does this mean that some Acroporas may begin to recess then just as quickly stop and begin new growth? <so many reasons for healing and receding. Cannot be summarized as such> Also I have a Stylophora pink...again its showing good growth, but there are spots of some kind of algae with fibers that seems to be spreading, although very slow....what should I do about this.  <Hmmm... very indicative. Stylo's also require massive water flow. I'm wondering what your flow is? The old rule of thumb at 10X turnover is pathetic and antiquated for modern reef tanks. I myself am running about 2400 GPH in a 50 gallon. It is dispersed in random turbulent patterns. You'd never guess it to be that high by looking at it... but the corals know! Do consider> I have placed this Stylophora at the end of a powerhead for better circulation and I occasionally will use my hand to fan away the algae. <Arghhh... please no linear flow (in front of the PH). Such reef corals need strong surge or random turbulent flow. Few reef corals will tolerate linear/laminar> Regards, Dennis <best regards, Anthony>

Staghorn Acro and specific gravity Hello WWM crew, <<Hi Charlie>> I did a search here on specific gravity and couldn't find exactly what I was looking for, so here goes. My current specific gravity is 1.027,and the polyps on my green slimer are not opening up fully. Do I need to do a water change using fresh top off water only to reduce the SG, or is there another way to reduce the SG? My usual target is 1.025. Please give me a hand!!!!! Thanks, CE <<You want to do this slowly over a minimum two days, .01 per day, removing some tank water and replacing it with buffered, aerated, heated FW until you reach your target. I doubt it's the SG causing your slimer to not open, but do lower SG to 1.025 and test your water for wastes and also pH, calcium, alkalinity, magnesium, etc. Make sure circulation is up to par for your slimer, needs good current. Yours, Craig>>

Unidentified Coral - Montipora SPS Hi guys, not sure who'll be responding so I'll address in plural.  <and if necessary, I'll answer in stereo...> I've been reading and appreciating your FAQs for a few months now (ever since I started my reef project about 3 months now) and was wondering if you might be able to help me identify this coral I saw at the LFS. The owner said it MIGHT be a type of Acropora but it doesn't match any of the photos I find to my satisfaction.  <close.... it is in the family (an Acroporid), but it appears to be a Montipora... likely M. digitata> I was thinking maybe it was a type of Anacropora or even Montipora. <bingo on the latter... and one of the hardiest SPS around. Very adaptable to a wide range of light and water flow. Like all SPS it needs very consistent calcium and alkalinity dosing though. Weekly testing, daily dosing as necessary to maintain in optimal health. Really a very hardy species though. Fast grower once established too. This specimen has seen better days but certainly can recover> This specimen has some bleaching in its center that I think may be due to close proximity to a Euphyllia parancora.  <oh, ya! That will do it> My tank is 36x21x12 (roughly) I consider it a 40 tall? I don't know really. The tank was a hand-me-down. Currently I've got an All Glass Aquarium power compact fixture with two 55w 50/50 bulbs running on it about 14 hrs/day.  <very modest lighting... for success with corals these bulbs need to be fresh (less than 10 months old), close to the water (no more than 3" from surface) and corals need to be in top 10" of surface for optimal health here (long-term success). See here my friend: http://www.wetwebmedia.com/marlgtganthony.htm > My other animals are 1 yellow tailed blue damsel, one blue mandarin, one Fire Fish, one sand sifting star, one red serpent star, two Mexican turbo snails, one feather duster worm, one reddish looking mushroom that rode in on some live rock, 3 small green stripped mushrooms, one Platygyra sinensis (on the substrate), one Euphyllia Parancora (on the opposite side of the tank about midway up), and some yellow polyps. Any help would be appreciated about this specimen <hmmm... do consider a larger tank soon or at least a fishless refugium for the mandarin. The sand-sifting starfish also will not live to see 2 years old if even one in this smaller tank. Not enough sand surface area for deposit feeding on organic particulates.> Thanks! Arthur <with kind regards, Anthony>

Acro Mower Hi Bob <<Good morning, Lorenzo here filling in for the rest of the crew, off at MACNA in Texas.>> Yesterday morning I noticed that one of my staghorns had an eaten path carved in it. Something had sucked the polyps right off. <<Yikes!>> I'm looking in the tank to see what could have done this. I found a weird snail with a long trunk not far from where the stag is. Do you know of any snails that eat SPS? <<Definitely, but not very common.>> What else should I be looking for? <<There are a number of animals that will do this, including snails, nudibranchs, and sea-spiders (quite rare, but sometimes seen, and does exactly that). At least if it's a tight, "path" you can probably rule out your fish. You may need to observe at night, with a red or blue flashlight to uncover your killer... Good luck! -Zo>>

Acropora bleaching question I just acquired three pieces of medium Acropora which came in fine. <be careful of such statements or beliefs. Most corals are somewhat to severely stressed for the first couple of weeks on import. Its just not that obvious unless flesh is falling off> After slowing acclimating to my 30g holding tank (before I put it into the main tank), it was fine for a day. Then the next morning (2 days after acquisition),  <yowsa... a problem already my friend! A mere two day holding period was more harm than good. This animal that was put through several changes in lighting (and extended periods of darkness) on import had to go from another lighting scheme at your vendors holding tank to your holding tank to your display tank all within the same week. Such drastic changes are a great burden on the limited resources of a coral. A longer QT in mod light with mod to heavy feeding would have been better. 4 weeks is a proper QT acclimation. Also, do review the following: http://www.wetwebmedia.com/acclimcoralslight.htm> the whole tank was cloudy and everything in that holding tank was dead (2 snails, a small Kole tang). All three pieces of Acropora were bleached white. I guessed something caused it to release its zooxanthellae.  <stress indeed> Anyhow, my question is this, will these pieces of Acropora slowly recover their zooxanthellae or are they pretty much dead.  <that depends on if the corallum is denuded of tissue or the tissue simply bleached pigmentation. If the latter, then yes it will recover. You should see clear polyps extended conspicuously if so. Heavy feeding with zooplankton will be critical then (do so in a small QT please). Live rotifers would be excellent> They were fine 24 hours ago, and have been moved to the sump of my main display. Thanks Jim <Jim... moving any coral is truly one of the most dangerous things to do. Even moving an established coral 2-3 times in a week can be enough to kill it. It is a bad habit, my friend and has contributed to the demise of this animal at least to some extent. To better days... Anthony>

Acropora bleaching? Hi guys, 'hope you're all well. <Anthony and Steve here in San Diego with Bob... drinking beer and answering e-mail. Yep... we're very well <smile>> one of my acros, dark purple valida is starting to whiten, no peeling off just white. Is this due to a loss of light as it has now grown nicely and maybe overshadowing its base. Also it's been quite hot these last few days and the temp gradually reached 83. <many possibilities for bleaching... light shock (water change, new carbon after absence, etc), lack of nitrate/nitrogen/feeding, and of course temp as suspected. If increase was 3 or more degrees in 24 hrs, then it is a real candidate> Could it be a lack of a certain vitamin or maybe even strontium. <not likely> All parameters are great, the tank is 2 years old and the valida is the only of my acros which is giving me trouble. Any info would be great, thanks. <my regrets, but not enough info my friend. Do consider the above possibilities> Stefi/London <best regards, Anthony>

Re: Acropora bleaching question Anthony, thanks for the response. I wasn't doing the QT for just a few days. It was meant for several weeks. That is how I have always acclimated my corals and has worked well.  <ahhh... I misunderstood. Thanks you and kudos to you for the good technique> It allows me to gradually acclimate their lighting to what their position in my main tank is. I'm sorry if you got the impression that I was just putting it in there for 2 days. . . <no...thank you, my friend. The limitations of e-mail :)> Still not sure what would cause it that would cause the entire tank to go milky white and stink. Very possibly the little Heliofungia that has been in there for awhile.  <indeed some rotting tissue> This tank is fairly stable as it is my coral acclimation tank. Oh well, thanks for the input and yes I agree with your assessments about stress. Now I'll just have to slowly nurture this back to health in my qt tanks. Jim <yes... corals are amazingly resilient! If there is any tissue still left, it will likely survive. Good water flow and feedings are the key for now... lighting not so much. Kindly, Anthony>

Browning Acropora Hello BAS, I've been an avid aquarist for quite some time and have read this column more faithfully than I've gone to work. There is no point in attempting this question with my LFS, as they are currently feverishly culturing Aiptasia anemones for sale (despite my unsolicited advice). My question pertains to the browning of SPS corals. I not-so-recently purchased a pink Acropora loripes despite my measly three and a half watts per gallon. I thought that if I placed the coral high enough in the water column that it would negate the fact that I didn't possess the high wattage usually required for this type of coral. I soon noticed several Aiptasia anemones of my own on this specimen, but unlike my LFS, I quickly dispatched of them with injections of Part A of the C-Balance duo. But with the bad comes the good and I also discovered a red Coco Worm with bi-lobed crowns attached to the base of the coral. The A. loripes itself has grown, which is quite apparent by its base coverage of the live rock I attached it to. My disappointment is that the color that was originally bright pink has now darkened into an almost rust color (It's been brown for over six months but still growing). Most sources indicate that the browning of SPS corals is due to inadequate lighting and an overabundance of symbiotic algae, but none discuss the reversal of this condition. For this reason I have recently up-graded to metal halides. My questions are, how do I acclimate an entire reef tank to two watts more per gallon, <It would be great if you have a lux-meter. Start the MH's up pretty high so that their output matches that of your current lighting. Another trick is to cover the tank in several sheets of vinyl window screening to cut back on the amount of light entering the tank. Then gradually lower the lights and/or remove a sheet over the course of several weeks. If you cannot verify the difference in output, attempt to make an educated guess by referencing the work of Dana Riddle, Sanjay Joshi, and Richard Harker. They have all conducted studies on various lighting setups and lamps and they may have comparison info about your old and new systems.> and do you have any suggestions about the Kelvin of the lamps I should purchase? <I like 6,500K Iwasaki lamps and 10,000K Aqualine-Buschke or Ushio lamps.> I am a big fan of D. Knop and he suggests for most tanks with invertebrates that are found near the surface ( I have two four inch T. Maximas as well) nothing higher than 6.5K, but I have read many online magazines as well as advertisements in TFH tout 10K as the ultimate true white light. <Some 10,000K lamps are quite good, but many are just marketed and hyped well. Most 6,500K lamps could use supplemental actinics for appearance. They do have enough blue light for good photosynthesis without it, but they have so much red, yellow, and green, that to our eyes the corals may not appear pleasing.> I'd just like a little information on the reversal of browning and how it has been achieved, as I've noticed recently, even some online suppliers advertise SPS that will color up with the right lighting. <Increasing your lighting is the way to correct the situation.> Thanks, Andrea <You are welcome. -Steven Pro>

Marine Light/ing hi sir Fenner, this site is great.. my question is lighting duration and intensity. I have a mini 8 gallon tank running one 32 watt 10000k daylight and one 32 watt actinic. My friend say to have the actinic come on for about a hour prior and then switch to daylight for about 8 hrs and then finish off with the actinic for another hour.. Is this correct.. <Mmm, the use of actinic is about right... overlap the actinic with the white, and I would extend the time frames... to 12 to 14 hours per day> My local fish store told me to have both of them at the same time.. Which is correct.. I have switched to having both at the same time but the Acropora started bleaching.. is there any way to save the Acropora?? <It should "photo-adapt" to the bright, mixed light in time> is the lighting too strong for Acropora?? <Possibly... try fewer hours or shielding part of the light if you can't dim it electronically (like with aluminum foil over part of the lamps) for a few weeks. Bob Fenner> thank you for you time sir.. <You are welcome my friend.>

Acro lighting.. Hi Bob, How's it going?  <Muy bien mi amigo> I hope well. Well my studies at Vandy are going slowly, but I still get a chance to stop by my house and take care of my corals only 30 min away). Well, I have this question for you. It's about lighting a 20 gallon long tank for Acropora. I know that you get all kinds of questions about lighting and I have read books and some of the FAQ's on this site but I still get confused (Sigh). <Me too> I was looking to light the 20 gallon using 55-watt power compacts. I have one 7100K bulb and I think another of the same K. I am planning to add 40 watts of N.O fluorescents, one actinic and the other actinic white. Well I was thinking and I wanted to ask you, should I use the 10000K bulb and an actinic on the power compacts?  <Hmm, yes... would be nominally/minimally better for this setting> I'm not totally clear on the Kelvin color thing. Could you clarify?  <Re Lord Kelvin? As a measure of average kinetic motion? Take a look at a photography reference work> Well I got to head back to Vandy. Oh thanks for the other questions you've answered and future ones you will answer. I love WWM. It fills my day with joy reading the FAQ's after a hard day of hard work. Thanks, Eric <It fills my day with that work!> P.S I'll keep studying on my corals and fish because I enjoy them way too much (my future job hopefully) <No such thing as way too much. Bob Fenner>

Picture of unknown SPS coral Sorry the picture isn't too clear. I'd like to identify the coral if possible. Any help would be appreciated. <Looks like a species of Montipora, of the family Acroporidae... here's a link/URL to the part of our site with images of this genus: http://wetwebmedia.com/acropori.htm Bob Fenner> Thanks, Todd

Acropora whiting out, 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 livestock, what purposes? Should be fine for low-light using livestock for maintenance> .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??. <Not necessarily... a MH will be quite hot (thermally), and this size, shape tank is hard to dissipate heat in... I would save this money for other purposes> ..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??, <Maybe... is there algae growing over the exposed skeleton?> why would this happen???  <Could be a myriad of things... please see the Coral health section of our site: http://wetwebmedia.com/corldisfaqs.htm> will this process have any effect on the other corals??? <Depends on the cause/s here... likely not if it has not already... could be lighting (is the colony up near the source?), predation, lack of nutrient, interspecific competition...> 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 <It sounds like you know what you're doing, and have a bunch of background in the hobby... have you read/re-read Borneman's Aquarium Corals, Fossa and Nilsen's v.1 Modern Coral Reef Aquariums recently? I suggest you do this to refresh your memory about basics here. Bob Fenner>

Technical Staghorn Info. Thank you much for your help. I greatly appreciate it.  Are there any particular Acropora species that are "less demanding" when it comes to lighting. Or is it mostly dependent on the zooxanthellae pigments? <Yes, to a degree.... and always... what do you really want to know... where to search out information/specifics on staghorn corals?... > Which pigments develop in the presence of which intensities in nature? <Ha! really? I'll look this up if you're serious...> or are the Axial corallites the areas that develop the radiation-specific pigmentation? <The axial corallites, the more significant salient identifying characteristic of the family (Acroporidae)... these areas do develop more and some different photosynthetic pigments... and storage foods.... that lend their apparent coloration> (not worried about water quality or circ, got those ends pretty well covered) lighting Brand-spankin' new 10,000 k 18" Coralife tube 2 month old 50/50 6500k/actinic 3 18" Coralife tube I ask because this is only (Yikes!) 30 watts over a 15 gallon high.  I am less concerned about protein skimming after discussions with curators from Mote Marine Lab/Aquarium (don't know if your familiar with them) where I volunteer. <Yes, know the place, people> Their experience shows that mature reef tanks with continuously optimum water quality (w/out water changes) would actually not be affected at all by protein skimming and might starve beneficial bacteria or microbes and that it is not necessary.  <Not indefinitely> I have to admit (more like brag), my tank has been up and probably overstocked since last July, and I have never had a problem with water quality. As a matter of fact I went 2 and a half months w/out a water change (shame on me, I know), and when I finally made a 25% change the water was still well <10 nitrates.  thanks once again Chris >> <What does Zig Ziegler get credit for..."Nothing succeeds like success"... more power to ya... If what you're doing works for you... Bob Fenner>

SPS hah! what have I gotten myself into now. I've been eyeing an Acropora formosa at the store four about a month. I checked all the signs. No algae complete polyp coverage. Its apparently so small that nobody wanted it for their big tanks. But me, I come along with my 15 gallon in which it would look of substantial size, the boss gives me an incredible deal because it hasn't sold. I'm acclimating it to the light like you inform on your site as I write. no ammonia, nitrites and less than 5 nitrate. test for calcium alkalinity and CaCO3. my lighting is a 10000 K and a 50/50 HO tubes. no skimmer. (the eclipse) Any advice PLEASE..... do you think it will survive or kick? is my lighting substantial? Beautiful blue-pink tissue, would absolutely LOVE to have it survive and flourish.  MUCHOS MUCHOS GRACIAS, Chris Survive and flourish, even retain it's color? Only time will tell... I definitely would modify the Eclipse (tm) and get a skimmer on this system... and keep looking, prompting me, and I'll post more of my SPS, Acroporid materials on the WWM site. Bob Fenner

Re: SPS ah, that feeling of elation and stupidity that courses through the body as a bold, (stupid) inexperienced (dough-blowing) aquarists mindlessly yet enthusiastically states those three magical words, "bag it up," is unrivaled. Day 2 - polyps are extended beautifully are a bright red against the pinkish-blue flesh (retracted slightly after the lamps were on for about fifteen minutes this is normal right?). Growing tips are a stunning shade of light turquoise. No wonder Acroporids are more like Rolls Royce's of the Anthozoan world. By modify my Eclipse, How so? not enough lighting?  thanks again Chris >> Oh, well written, posed... Yes to most Acroporids being "open" at night (to feed), though most can be trained to be more open during the day. Modification probably refers to cutting the top back to fit a skimmer. Bob Fenner

Acropora and crabs Hello, Are the small crabs found in Acropora harmful to the coral? >> Not generally... all else being equal they're of no consequence. Bob Fenner

Acro Sel. < Hello Bob-I have ordered fifty pounds of live sand from FFE as a "refresher" for my ten years old deep sandbed, and want to start adding small polyp scleractinians to my tank. The tank is 2' high by 2' deep by 4' long, and will have two 400W 6500K metal halides over it. It is filled about 25% up from the bottom with live rock, and is hooked up to a sump with two large Tunze skimmers and a Fluval 403 filled monthly with ESV GAC. What corals should I start with? Thanks, Kurt Seidler >> In my opinion a few Acroporid fragments would be best at this time... Ffexpress sells captive fragged staghorns as do many local shops and independent hobbyist/fraggers... look around... and in a couple of months we'll talk. Bob Fenner

Acro ID ok, thanks...but in the mean time after looking at some old issues of FAMA have determined that my Acro is more structurally similar to valida rather gemmifera <good luck on morphological second-guessing this genus... time for genetic mapping/karyoptyping> , which is a relief considering the lack of adaptability you claim gemmifera exhibits in captivity <just an average...> ... there is NO sign of my polyps. the tissue is living and completely covering the skeleton and even the hunk of rock that accompanied it, except the polyps structures seem empty...hollow almost... the axial corallites are big and way out, and haven't faded like the rest of the colony. I checked the tank every hour all evening , and they were still recessed, even where the previous dark color remains intact...hold on, going to check again...nope, still no sign of any extension. and here its 9:00 PM. and during the course of the day, the tissue darkened just a scoshe (scientific unit of visual color/light spectrum reflected from living organisms under the refractive/reflective qualities of water - ok, for lack of better description of the amount of color change, I made that one up)<actually, taksan scant transliteration... wakarimasuka nijongo?... of a Japanese diminutive> ...just had an epiphany...WHEN I succeed in having this Acropora thrive grow and regain all its glorious color, I want to take genetically identical frags in separate <ate> systems, and publish findings of experiments with the function equations and pigmentation along with the most efficient/appropriate filtration (adding other species along the way)...oh the possibilities are pooling like phosphates! - maybe even write a book. OR A COLLEGE THESIS! what stroke! Your input through experience and further education would be greatly appreciated (any suggestions on how to set up the experimentation systems, etc?)  Anyway, any help you could offer with the situation at hand would be even more appreciated thanks again, Chris >> <Wowzah, glad to... time for many rep.s and a trip or two to the S. Pacific... and much discussion of experimental models... just hold on in the meanwhile... we are stuck in the analog one-time through treadmill... as you know. Bob Fenner>

Acropora ahoy! "What was I thinking?" "It cost you HOW much!?"  "Throw it in there and pray!" "Yeah, that's a nice one." "HA! goooood luck!" Well...so far I've had more luck with SPS than with MPS or LPS, so what the heck. The colony (Acropora gemmifera as far as I can tell at the moment) is 3" across and 2" inches high, and NOW I know what an axial corallite looks like. been eyeing it for 2 weeks since it came in. perfect coverage, extension. the retailer didn't even have it under direct lighting. So the adventure starts... do you think I'm crazy? Chris  >> Not crazy, perhaps just enthusiastic (From the Gk. meaning "the god in you", en thuus, hence the term theology...) Do take a look at the A. gemmifera and other pix I have placed in a survey piece (the "Acroporidae") on the site: www.wetwebmedia.com... More info there re the selection and care of these quintessential SPS'. Bob Fenner

Re: Acropora ahoy! uhoh. Went out in the Gulf for Spanish Mackerel and Cobia today. When I got back, my new Acropora (which was very dark burgundy when I got it) abruptly (in less than 12 hours!) had changed is tissue color to a light tan-orange. (1 or 2 branches were still dark), and the polyps were expelling the zooxanthellae w/mucus strands. The axial corallites have not faded however. Did I waste my money (I won't give up on it until its dead or thriving)? Is this even necessarily a bad sign? If it is, is it treatable? thank you, Chris (PS, I am extremely stubborn and do not give up on anything, especially corals, so I am definitely an optimist, and don't ever tell me that something can't be done or at least attempted, because I'll stand firm and accomplish it or at least try it, and for the moment, the death of my Faviid polyps has ceased to progress any further after supplying it with augmented circulation)  >> Ah, good to hear... not a good change in your staghorn... but not the end of its or your world... Bob Fenner

Re: Acropora ahoy! Though I'm disappointed in the color fading in my Acro, and distressed to hear that its a negative change, the colony really doesn't look any worse for wear this morning (no bleaching, etc.). maybe the color will return eventually. Chris >> Yes... the coloring is a "chicken-egg" type of situation... the predominant pigments residing in your Acroporid are a function of what's available (made by its zooxanthellae), chemical, nutrient, physical (circulation, dissolved oxygen, carbon dioxide, alkalinity, light quality/quantity/duration, presence of other bio-chemical agents (from other livestock).... and many other considerations... You can and do easily effect the color... as you will find. Bob Fenner

Re: Acropora ahoy! pigments or a "function" of what's available? is that like f(p) = x + y + z +... f(current pigmentation) = x + y + z (sum of phys, chem, and light, etc. variable interactions and effects)? <Yes, if you'll allow the addition of a couple of qualifying additions (derivatives, chain-rule extensions, exponentials... to some of these variables... Like the Maxwell-Beerman Light Extinction coefficient (e to the minus ir...)> so by variable manipulation (after acclimation is complete) the zooxanthellae pigmentation (function) will change and develop accordingly? Chris >> Or simple time and variability going by... Bob Fenner

Acropora crab I purchased a table Acropora about 2 months ago. Last week my UV sterilizer broke and it feel victim to a bacterial infection. My question is about a  small crab that was living in it. Will it die living in a dead coral. I have a healthy 1 year old Cats Paw. Should I try to remove the coral crab  and place it in with the Cats Paw.  >> I wouldn't... if the crab thinks it can/should move to the (Pocilloporid) Cat's Paw Coral, it will of its own accord... The Acroporid may well still be alive... Bob Fenner