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FAQs about SPS Coral Behavior

Related Articles: SPS Corals, Acroporid Corals, Dyed Corals,

Related FAQs: SPS 1, SPS 2, SPS Identification, SPS Compatibility, SPS Selection, SPS Systems, SPS Lighting, SPS Feeding, SPS Disease, SPS Reproduction, Acroporid Corals, Agariciid Corals, Astrocoeniid CoralsMerulinid Corals, Pectiniid Corals, Pocilloporid Corals, Siderastreid CoralsStony Coral Behavior, Coral System Set-Up, Coral System Lighting, Stony Coral Identification, Stony Coral Selection, Coral PlacementFoods/Feeding/Nutrition, Disease/Health, Propagation, Growing Reef CoralsStony Coral Behavior,

Behavior is influenced by many things... including tankmates.

SPS don't grow... Nutrient deficiency likely    2/17/08 Hello all, I have a 75 gallon sps dominated system that has been up for a year and half. It has about 80-90 pounds of live rock distributed between the display and the 30 gallon sump. There's probably 75 gallons of total water with rock displacement factored. Octopus nw-150 skimmer. 10 gallon fuge section of the sump growing Chaeto. Display is lit with two 175 watt iwasaki 15k halides and two ATI blue +. Photoperiod of 10 hours. Flow is provided by two Koralia 3's and a modded maxi-jet 900. I have about 20 sps frags (a few that could be considered small colonies), xenia, Zoas, some Halimeda macro algae, and some GSP. A purple tang, red tail tamarin wrasse, scooter blenny, pair of Percs, and five chromis (just added) make up the fish load. Current param.s: Ph 8.0-8.3 Ca: 420-440 Alk: 9 Mag: 1300 no3: undetectable po4: undetectable (via Salifert which really isn't good for phosphate, can't afford a Hanna though...) specific gravity: 1.025. I don't feed corals, only fish. Feed a cube of prime reef and formula one pellets daily. I know feeding corals is recommended by you all, but I believe in fish poop as being a great food source. No noticeable algae, except stuff that appears on glass every 2-3 days. Five gallon water changes every week. My problem is with my corals, the sps in particular. They do not appear unhealthy, they have great polyp extension. For the most part, the Acro's and digis have decent color. The problem is, the corals get in my system, grow for a week or two, then stop completely. I have had many frags for almost 7 months that haven't budged. My caps are extremely pale and some Acros are as well. My Zoas are also pale and kinda halfway closed sometimes. What could be some possible reasons for this? <Mmm, the most glaring defect is the absence of food. You state you have zero phosphate? All life needs some HPO4... You don't list chemical filtrant use, but... do you? I would cease this, or at least cut it back... perhaps take up some purposeful feeding... a brand of Phytoplankton likely... DT's or such> I have a few theories that I couldn't find anything about online really. Maybe you could discuss them with me. I know its not the basics (lighting, flow, basic param.s). 1. Phosphate. I rid my tank of phosphate via Chaeto, water changes (ro/di), and Caribsea's Phosbuster. <Oh, here it is> I know phosphate really inhibits calcification so I was thinking maybe there is high phosphate (Salifert would detect it about .5 at least, so couldn't be higher than that.) that I can't detect. Phosbuster supposedly binds to phosphate and turns it into dust (or something along those lines) that can be skimmed out. Perhaps some of this "dust" is affecting growth. <Perhaps . Much more likely it is absent... and essential> 2. Potassium. I don't test for it, not many do, but i hear a lack of it can stunt growth, and make Monti caps, esp. red ones, very pale. This seems like it could fit, but I found mixed feelings about potassium on the web. <Potassium is rarely rate-limiting in captive aquatic systems... hence the paucity of discussion, products sold...> 3. Lack of nutrients. Perhaps my tank is "too clean". This would be a nice thing to hear because, as an sps keeper, clean water is an important goal. Perhaps I should feed more and let my trates climb to 5 or so. This seems like it would fit with the lack of color in some corals, but not sure about growth. <I do agree with this> Those are the possibilities I came up with, but please let me know what you think about them and others you may have. I appreciate it very much. Have a nice day! -Mark <Remove or vastly cut back on the chem. filtrant use, add more foods of use... Perhaps an iodide-ate supplement weekly, along with the small water change. Bob Fenner>

125 Mixed Reef- Lighting and Coral Color Question- Purple Cap From -- 09/12/08 Bob, I love your books. Any new ones on the way? <Always some project going... but no "due out" dates> I bet you get tired of all the emails concerning lighting and water parameters but here is one more. I have been trying to get the color to come back on a large purple Cap colony for over 1 year after my tank move. I moved the corals from a 75 to a 125 (6 foot tank) reef about a year ago. My current setup is as follows: 80 Pounds Fiji Live Rock 25 Gallon Berlin sump with 3 filter socks <These need to be cleaned, likely every day.> Two Euro Reef RS-80 Skimmers Phosphate Reactor <This too is very likely a factor... "corals" need soluble phosphate... I'd ditch this unit> 2X250 Watt XM 20ks with PFO ballast (new bulbs 1 month ago) In center of Canopy- 1-96 watt PC Actinic 03 and 1- 65 Watt 6700k PC Carbon is changed every two weeks and is run in a sock in a sump chamber Small Chiller Water: Salinity 1.025 No measurable ammonia, nitrite, nitrate, or phosphate <Again...> with Salifert kits. Calcium 400-420 and Alk 8-9 DKH with Salifert kits I do a 30 gallon water change once a month. Fish load: I have 6 fish including two angelfish and I feed daily. One of the angel fish is about 4 inches and I have a 4 inch Maroon clown (10 years old) The other fish are small (damsels and a six lined wrasse). My question concerns the color of a large purple Cap colony I have on the right side of the aquarium. The bright purple color turned mostly grey with purple polyps after the move to the larger aquarium. The color changed/faded within one or two days after the move to the 125. The colony is directly under one of the halides and is in the bottom 1/3 of the aquarium. The Halides are about 10 inches off the water. The colony is about 10 inches by 10 across and is attached to a large rock that cant be moved easily. I want the Cap to regain its bright purple color but growth has slowed and the color will not come back. Do you think I have enough light on the tank to get the bright color back? <Yes> I had some color improvements in other corals> in the tank by increased feeding of the fish (Rods Food). But so far no improvement on the CAP. I really do not want to change to 400 watt Halides due to increased operating costs (and initial cost) + the added heat and I do not like the look of 10k bulbs. Any suggestions would be greatly appreciated. <Clean your socks daily, ditch the phosphate remover... This will likely "do it" in time (months). Bob Fenner>

Browning SPS -- 03/27/08 Many of my SPS that are toward the back of the tank are browning on the side facing the back and many are brown on the lower half or third of the SPS. Is this normal because light is not reaching the bottom of the SPS and maybe there's not enough light at the back of the tank? <<There are many things that can cause corals to 'brown,' but based on your statements, yes, I think it is likely due to a lack of light intensity/spectrum in those areas>> Is there any way to compensate for this or is this normal to only have color where light shines? <<'Compensation' would have to come in the way of providing enough light from all angles (a common problem in most hobbyist's systems), to include a reflective substrate (Aragonite sand). Moving the corals more toward the centerline lengthwise in the tank should provide better color on all sides'¦adding more lights front-to-back and/or upgrading to better reflectors would also probably help>> Thanks very much for all your help. <<Happy to share. EricR>>

Can't get the BLUES... color coral sel...  07/28/07 Hi WWM Crew! I have a 1 year old 75gal mixed reef, which is slowly becoming SPS dominated. I run 2x175 Iwasaki 15K MH bulbs, supplemented with 4x96watt PCs (2 67K and 2 Actinics). MHs are on for 7hrs a day, and the PCs are on different times of the day for a total of 10 hours. My SPS that are pink, red, purple, green, and orange are doing great in growth and coloration. However, any SPS that has blue coloration quickly turn brown, although they grow just as well as my other SPS. Currently I have an Oregon Blue tort, and ORA blue tort, and a German-blue polyp digitata. All 3 of these are turning brown. Do sps that have blue coloration require higher temperature bulbs? <Not necessarily. In fact, they may require less. Or it might even be what you're feeding them or something about your water parameters. Even in academic arenas, coral coloration is very poorly understood. (Maybe because, in these perilous times, coral researchers don't really care so much if corals are blue or brown so long as they're not dying.) In any case, your best bet is to find a blue colored coral that has been kept under lighting exactly like yours for at least several weeks (better if months). Please see here: http://www.wetwebmedia.com/spsbehfaqs1.htm> Should I add more actinic lighting? <Likely the only thing that will do is make everything *look* a little bluer.> I have all 3 of the blue SPS species at the highest part of my tank directly under the MH bulbs, but still they are browning. <So move them down and see what happens. It's something of a myth that corals only brown from lack of light. They can also brown from too much light (or for some other as-of-yet unknown reason). But in any case, the coral can still be very healthy, just not as pretty. If you just want some blue in your aquarium, you could think about a blue crocea clam. :-)> Thanks for any advice you can offer, Jonathan <De nada, Sara M.>

SPS TURNING YELLOW 01-01-06 Hello I just bought 2 SPS coral for my 55 gallon reef with  260 watts power compact ( about 5 watts per gallon) a canister filter,  protein skimmer,2 power heads, and a heater, about 30 lbs live rock, 40 lbs  live sand. Now for the fish I have a yellow tang, maroon clown, mandarin goby, and  bullet goby. My corals are a finger leather, yellow polyps, 2 mushroom  rocks, Ricordea, open brain, cabbage coral bubble coral , 2 SPS on the same  rock, and star polyps. My inverts are a sponge, emerald crab, camel  shrimp, coral banded shrimp, t. gigas clam, bubble tip anemone,6 astray snails, and a  large turbo snail. Also I have a medians hair algae, Chaeto ,needle  algae. My water tested perfect. <Sounds like a very full tank.> My new SPS coral that was a green brown  color is now turning yellow. The other day I had to catch a clown fish  and I took down the rock work to catch him. Is this because stress  did I kill it or is it new symbolic algae because lighting  please  help I love this coral thanks for the help. Sorry this letter was so  long. Please excuse the mis-spelled words I'm 11 years old thanks for the help love your web site. <First, let me thank you for the compliment. As for your question, you may have three situations going on. The first situation could be chemical warfare in your tank. To remedy this you will need to add carbon to your tank. The carbon will also clear organics from your water making the lights more useful for your coral. The second possibility is that you may be witnessing bleaching. If your coral is bleaching you will need to upgrade your lighting to keep that coral or remove the coral to a friend's tank until you can afford to upgrade your lighting. The final situation you may be witnessing is; the corals may be adjusting to your lights and will actually color up to a more natural color. This situation is usually found more in tanks with very high watt lighting and pristine water conditions. Travis> Color of SPS Corals - 8/29/03 This message is for Anthony Calfo <howdy> Anthony, first off thank you for all your prior help in my 75 reef.  It is  doing better today than ever largely due to your help.   I also have just purchased your book on Coral Propagation and an getting a lot out of it. <thanks kindly my friend> Setup: My current lighting is 2 URI 50/50 VHOs and 2 full actinic (440 Watts) + I added 2 96Watt Power compacts one each about 6 weeks ago (added one and waited 3 weeks for the other).  My alk I keep around 10DKH and Calcium around 350 using limewater dripped nightly.   <excellent numbers... keep steady and you do not have to worry about going higher. Or if you want Ca higher... let the ALK fall to 8-10 dKH> I also have to add about 1 teaspoon a day of Baking soda and about 15milliters of Sea Chem Reef Complete (3 cap fulls) to keep these levels with my current coral growth.   I am going to try your method of Kalk dosing you mention in your book.  I am also feeding the fish and corals  more now (your prior recommendations). <sweet> My question concerns the colors of my SPS corals in my mixed reef.  I am starting to get really nice looking purple and orange colors out of my Acros and my Montipora digitata.  However, some of my green Acros and Monti's are still not dark and vibrant as they should be.  (My friend,  the Halide nut,  wants me to go to HQI halides.  He has much nicer green colors then I do but my purples are better than his).  Does the green colors require more intense lighting or is it something else? <your friend is clearly mistaken... or at least missing the big picture. Cnidarian pigments are as heavily influenced by feeding levels and water clarity as they are the nature of light. Many factors here... with nitrate levels (zero is not good... allow a few ppm to linger) and UV penetration (not MH vs. PC... but glass canopy or no, being the issue here). That said... double ended HQI halides are excellent lamps. My current fave> Thanks again for your help. P.S. one note out of your book.  You mention coralline bleaching right at a water line when doing water changes.  I used to have a big problem with this until I turned off my fans during the change.   The coralline does not seem to die off any more.  I always thought the bleaching was due to the intense evaporative cooling with the fans on. <it really is a coincidence in your case... do consider that every piece of live rock imported is out of water for a minimum of 4-7 days dry on import. The reality of the industry is that unless you live in Los Angeles/port of entry... your rock was out of water for 7-14 days on import. Air exposure is not an issue here bub. By chance do your lights turn off with the fans? 'Tis light exposure then> Anyway, I really like the book and hope for a "part-two". Andrew <thanks kindly <G>... am penning the "Reef Fishes" volume of our new NMA series as we speak <G> Anthony>

Color of SPS Corals II - 8/29/03 Anthony, thanks for the quick response.    <always welcome> I am not sure I fully understand your answer.  "and UV penetration (not MH vs. PC... but glass canopy or no, being the issue here). That said... double ended HQI halides are excellent lamps. My current fave>"     <my apologies... to be clearer, coral coloration in some cases is a matter of UV exposure and not a matter of a specific type of bulb. No one bulb (not even HQIs ;) ]  can keep all corals in optimal color because some natural pigments are stimulated by UV (producing attractive colored proteins produced to reflect/refract it) while other corals are influenced unfavorably by it. You could have the "perfect" lamp, if such a thing existed, but with a glass or acrylic lens, your corals may not get the light they really need (for other corals... the lens is necessary to prevent excess exposure). Point being.., lenses clean... lenses dirty... lenses off and lenses on can all effect coral coloration. So can proper use of carbon (weekly/daily) to maintain water clarity or not. Coral colors simply are not only about lamp choice. And so... experimentation will be necessary> I did forget to tell you my tank is acrylic.  I do keep the top very clean though.   <yes... critical> Would you say the green digita may not be getting enough UV?   <I could not possibly say for certain... even if we could confirm the ID correctly, some specimens/colonies come from vastly distant areas of a reef and have evolved to need different light qualities> I am trying to feed more and like I said, my purple corals are really starting to color up but the greens are not dark enough.   <indeed... the feeding is crucial for maintaining coral coloration. And like the water clarity issues above, it is a double edged sword. Excess nitrate/feeding can over fertilize corals, so to speak, and cause an unattractive darkening (often brown). Experimentation> You are correct about the nitrates.  My tank do not register any with my kit (Salifert). <If your nitrates are truly zero... then do allow them to creep a bit (keep under 5 ppm though). I must say, however, that I am not impressed with Salifert test kits based on consumer feedback I hear> Also, I am considering metal halides for an upgrade when all my bulbs reach the 6 month point.   For my 75 reef considering it is acrylic, I am thinking of going to 2 175 watt Ushio metal halides and run two full actinic VHOs with my old Ice Cap ballast (going forward 4 bulbs to replace instead of 6).  Would that help "punch more light" to the corals and help with color?   <most definitely... a nice combination> It is less total watts than I have now but I feel the halides might be better here.   <correct... better penetration at depth> Also, would you recommend a different setup with an HQI halide setup with 2 150s or 250s?   <i cannot say without a list of species. We must [pick our species and identify their needs before selecting lights> I was worried about to much light and heat as I really do not want to over do it (heat is a concern as I do not want a chiller). Thanks again. Andrew <no worries... 150  watt HQIs at 6" off the water or 175 watt Ushios at 9 inches of the water will be nice either way, to generalize. Be sure to keep those fluorescents no farther than 3" off the surface though. Best regards, Anthony>

SPS Polyp Question - 8/20/03 Howdy Guys and Gals and anything else... <whassup :)> I have a quick question about Acropora frags.  I have a few types of Acro. frags as well as 1 small Acro colony.  They tend to extend their polyps only in the evening, which I read is normal. <indeed... they feed on micro/nano zooplankton and 'tis the time such matter comes out to play> Is there a way to have them extend during the day?   <tweaking water flow can help... but a timed refugium (cycling with display on a dedicated loop only by day and then simply circulated and batch treating water by night) would do the trick. We talk about such aspects at great length (more than any other book to date) in our new work "Reef Invertebrates" (Calfo/Fenner)> The PH is about 8.44 in the day and around 8.19 or so in the evening.  Is this too much of a fluctuation?   <slightly so yes... but has little to do with polyps extension> Should the daytime be higher than 8.4?   <I suggest a night/day range of 8.3-8.6 with a fluctuation of not more than .2 within it> My 90G tank has about 1900GPH of flow, <excellent> none of the frags are receiving any direct flow from the returns.   <as it should be> Calcium is around 400, dKH 9.  No ammonia, nitrites, or detectable nitrates. <all fine except the nitrates. SPS and most corals in captivity need a small amount (a few ppm) of nitrate to feed on - they will starve slowly without it. Color is affected too. European aquarists have taken to adding a sodium nitrate solution (.1% Knop) to nitrate starved tanks> The 1 colony I would have its polyps out for the first few weeks it arrived, but it does not anymore.  They all seem to be growing fine as well.  I have never seen any of the fish bother them, but then again, who knows what goes on when I am at work! Thanks, Paul <maybe they are bashful. Or instead... perhaps they are modest - you haven't been walking around the house buck nekid have you? You may have embarrassed them. SPS have delicate sensibilities. best regards, Anthony>

Wants to get it Bigger Hi guys. <How goes it, Michael here this evening> I'm hoping you can help me out. <Try my best>  Here's a quick tank profile: 90g/20gsump/20gref 2x250w 10k MH 1.025sg 79F. <So far so good> I'm in college, so most of my stuff is diy. <I think we're all poor as students :|> Here is my problem: I have been keeping my tank for 2 years now, 1 year in a 55g before I had to move, which I will have to do again this summer (not far- not that that means it wasn't a pain in the ass the first time). I only lost one snail during that move! <Nice>  Anyway, I have been keeping a little of everything, but few SPS. I have had good success with almost every coral I have purchased, and I even had a frogspawn return from a skeleton that had been dead for six months. <Have to love corals' recuperative powers in a healthy system>  I only have a few (8, mostly small) fish. Salinity and temperature are kept almost perfectly constant. My fish seem happy and soft corals, mushrooms and polyps reproduce fairly rapidly. I even have a neat pink sponge that has covered almost all of the undersides of my LR. I also have 3 clams- I have had my squamosa for about a year. <Are they all Squamosas?>  Anyway, things seem to be right, but the growth of my coral (mainly SPS) seems to be dramatically slow. I have a brown Acropora frag that I have had for over a year, and it has grown maybe a few millimeters. sad, huh? It's stuck out its polyps every single day and appears healthy, but there is little growth or encrustation at all, with some bottom-up recession. <When a coral appears healthy and extends polyps as usual, but doesn't actually grow much, something is deficient. Probably not enough food or not enough light. Acroporas are very light hungry corals (for the most part, there are many species in the Acroporidae genus), much more so than your mushrooms, as these species are separated by at least 60' of water in the wild>  I have a purple tortuosa frag that I have had for maybe six months- it hasn't receded, but the growth is almost nonexistent- definitely unlike the time lapse sequences of acros that I have seen. I have been using tech cb for quite some time almost everyday as well as Lugol's and I infrequently (~once a week) add other stuff like magnesium, trace elements, strontium etc in small quantities. I add a little plankton or black powder twice a week or so. Recently I purchased a ph probe to see if that was where my problem was. It was around 8.0 during the day, but I have brought that up by drip dosing Kalk steadily to around 8.2/8.3 and I'm shooting for 8.4. Sorry about how lengthy this is. Should I be adding more calcium/buffer or feeding much more plankton? <Well, your calcium levels should be around ~400 ppm if not closer to 450. Acroporas are very calcium needy, being stony corals. As for plankton, it will do them absolutely no good. If you've only been feeding plankton, this is probably why you're not seeing any growth, as they're slowly starving. Acropora sp. are very hungry, and need zooplankton to survive and flourish>  I thought that most of the corals were predominantly autotrophic. <Not nearly, they most definitely need feeding>  I am keeping the SPS frags in the highest flow areas of the tank. <Probably a good idea, but really depends upon the subspecies>  I have an orange capricornis frag that is very healthy looking and has shown decent growth (~1.5" in 5 months):(. Also, I have had various xenia colonies, which in my tank seem to move very rapidly across the rockscape (with little growth) and then they either stay the same size and look good or wilt. I know I'm doing something right because I have had my mandarin for 1.5 years and a leopard wrasse for one, a colt coral that I grew from a small piece and now have to prune, and my tank is pretty cool looking (but I have nightmares about some aquarium hotshot coming in and catching all of the problems I know I have). If you need anymore info, just write me back. I want a COLONY, not a one year old frag. thanks so much, Hunter Leber <What all are you feeding? What is your current lighting? A bit more info might help us get to the bottom of this. M. Maddox>

SPS Polyp extensions Hello: <Hi Brian, MacL here with you today.> I have a few questions I am hoping you can help me with.   First of all my tank: 265 gallon 3 175 20,000k MH's 4 96 watt PC's 2 actinic and 2 white light 100 gallon sump with a mega protein skimmer 30 gallon refug with 2 types of Caulerpa and a PC 7 power heads 500lbs live rock 3in aragonite 1/2hp chiller WATER 1.024 380 cal 10dkh alkalinity 0 nitrate 0 nitrite 0 ammonia Bionic and Kalk daily LOTS of tangs, fire shrimp, cleaners, hermits, emeralds, 3 red bubble anemone and more livestock all reef safe. I have 40-5- diff SPS colonies and frags. A few SPS frog spawn  brains etc. I have 2 softies one is huge but not waxy now. The bottom line is the SPS have not been in the tank long and I am getting little polyp extension. <Could be a few different things. Could be the spectrum of the lights, the depth of the tank and the positioning of the corals in the tank.  You don't say how tall your tank is nor do you say how deep the corals are positioned. The 175's may not be penetrating as deeply as you need in the water. I would also be a little concerned that your calcium is a bit low for SPS. How frequently do you do water changes? Good luck and let me know if we can help you in any other way.  You'll find numerous FAQs on the site about how to raise your calcium and keep your tank in ionic balance. MacL> Tank has only been up 4 months. Is there anything I can do to help.   Brian

Re: SPS Polyp extensions Thanks: <Hey Brian, MacL here again> The tank is 30 inches tall. Most of the SPS are within 12 inches of the surface. I am doing water changes every 3 weeks. I will check my calcium again to ensure accuracy and proceed with raising it. The big question I have had is that some of the colonies are doing fantastic and others are not. Any ideas why? <Could be a million different reasons, like the lighting they came from before they went into your tank, or some stress that they received, something in your tank eating on them,> Could this simply be due to the tank only being up for 4 months? I did allow it to cycle for 5 weeks before adding any livestock.  <A tank does take time to age and become stable and when its unstable its hard on corals. I didn't add any corals into my tank until it was over a year old because of that although I do know people who have been very successful with newer tanks but they constantly work to achieve that stability of calcium, ph and basics in the tanks.> Brian

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