FAQs about Coral Placement 1 Related Articles: Coral Placement, Coral Feeding, LPS Corals, True or Stony Corals, Order Scleractinia, Propagation for Marine Aquarium Use, Acclimating Symbiotic Reef Invertebrates to Captive Lighting,  Related FAQs: Cnidarian Placement 2, Growing Reef Corals, Stony Coral Identification, Stony Coral Behavior, MH burned Nephthea... start them lower or shaded if going to boosted lighting from lower intensity or the wild.

Attaching "Sinularia flexilis"
Hello! <Hi there, Paul at your service> I recently purchased a "Green Finger Leather" ( Sinularia flexilis) from my LFS. It is quite nice and it has been adapting on the bottom of my tank.<Very good> The tank is 24" deep.
I would like to place him now near the middle of the reef in some moderate water flow, but how do I attach him? <Oh, well, many forms to use here, epoxies safe for aquarium use like Aquarium Systems Holdfast product, Cyanoacrylate based super glue gels (many to choose from here) check your local home improvement store for Cyanoacrylate based gel glues. Also, at the
Monterey Bay Aquarium, they use a product called Z-SPAR. Look around for it.
It is a marine epoxy sometimes found at boat stores and home improvement shops around the world.> I fear that he will be knocked off his perch by either the water current, crabs, star fish, or whatever else I have in there. <totally understood> I can not remove the Fiji rocks from my reef without upsetting the whole reef!
<Also u
Thanks, <No worries. Paul>
Jeff

Re: Attaching "Sinularia flexilis"
Hey Jeff. I may be out of town this weekend so if you can send the original question ASAP that would be grrrrreat! I may get to it at latest Monday. I am so sorry about the missing text. Sheesh, what a rookie maneuver on my part. Take care!
P.S. For the most part, regarding your question, I believe you would not need to remove rock even if you were to use Super Glue Gel or something to that effect. I put a little on my finger and dab the spot where the coral will be placed, and then put a little on the piece of rock for which the coral is attached. Then combine the two and hold in place (underwater) for a minute or two. Also, there are Epoxy sticks that can be used such as Aquastik or Holdfast See here: http://www.drsfostersmith.com/product/sc_view.cfm?siteid=6&pCatId=3771 or do a search on google for other e-tailers. Also, we use at the Monterey Bay Aquarium a product called Z-spar Splashzone epoxy from a company called Z-Spar. It can be found in the Western Marine catalog (online) You will never have to buy epoxy again though as it is $99 bucks and should last you your life time. You can pass it on to your kids!!! Hope this helps!

Attaching coral to live rock - 2/25/03
Hello! <Hi there, Paul at your service> I recently purchased a "Green Finger Leather" ( Sinularia flexilis) from my LFS. It is quite nice and it has been adapting on the bottom of my tank.<Very good> The tank is 24" deep. I would like to place him now near the middle of the reef in some moderate water flow, but how do I attach him? <Oh, well, many forms to use here, epoxies safe for aquarium use like Aquarium Systems Holdfast product, Cyanoacrylate based super glue gels (many to choose from here) check your local home improvement store for Cyanoacrylate based gel glues. Also, at the Monterey Bay Aquarium, they use a product called Z-SPAR. Look around for it. It is a marine epoxy sometimes found at boat stores and home improvement shops around the world.> I fear that he will be knocked off his perch by either the water current, crabs, star fish, or whatever else I have in there. <totally understood> I can not remove the Fiji rocks from my reef without upsetting the whole reef.<Also understood> He is attached to two pieces of rock about 1 inch in length each. Is there a reef safe glue/epoxy that can be used under water that is safe? <See previous statement> This is my first coral I've had to attach without removing the rocks and "super gluing".<No need to remove rock to super glue. I use a rubber glove and put a few drops on my finger and then smear the glue underwater where the coral is to be placed. Then, I place a few drops on the bottom of the coral attached rock and quickly attach the glue smeared live rock. Hold in place for about a minute or so and should be fine.> Please help me with some suggestions.
Thanks, <No worries. Paul>
Jeff  

Gluing Corals with Cyanoacrylate - 2/23/03
Hey Gang!  How's it going? well I hope. <Things are well indeed, Scott. Paul in the hot seat today> I need to attach a toadstool leather to a piece of live rock. This coral has a small piece rock attached to the base of the coral itself, however, trying to keep the piece "wedged" in the rockwork is proving to be a futile effort. <totally understand!> I picked up some superglue gel with intentions to attach the coral to a stable rock. <Good> Now for the questions; even though the Cyanoacrylate gel is thicker than normal super glue, it's still thin. How long do I leave it in the freezer to thicken it up? <No need to do so.> When it comes to gluing the coral to the rock, what to do? take the rock out of the tank, dry a section where glue is placed, then apply glue & hold coral in place for 25-30 seconds? <Many methods can be applied here, but I personally put a little drop on a gloved hand, smear it on the rock where the coral is to be placed, then put a drop or two on the bottom of the rock with the coral on it, and attach the two together and hold in place for 30 seconds or so. No need to take any rock out of the aquarium in my experience. For the rocks with larger corals, I use an epoxy that can be found just about anywhere. Look for it in aquarium retailers and e-tailors. Same method. mix it together, then put a little on the rock where the coral is to be placed (yes, while the rock is underwater) and place a small piece on the rock with the coral on it, then place the two epoxied pieces together and hold in place for a minute or so. No problems. Done!> Then place back in the tank? <No need to take any rock out of the water> I haven't done this kind of thing before, so, I'm a little nervous about the experience <Nothing to worry about. Check out Anthony Calfo's "Book of Coral Propagation Vol. 1. Everything you need to know about corals, coral placement, and propagation can be found ,in all their glory, in one place.> I'm fixing to learn! <You're well on you way!> Thanks for the advice.  <My pleasure>       
Scott in Denver <Paul in sunny San Jose>

Stressed coral from move? 2/17/03
Hi, Thanks.  It is a reef....I will use the old 8 month old white until the new one arrives....any thoughts about the lighting having some thing to do with my pearl bubble not doing that well  (an understatement)
<not likely... bubbles can live in extremely low light. They simply need fed a lot>
He just keeps shrinking....polyps , brain and pagoda....all fine ....but that little guy just is struggling....
<is one of the other corals near to it (say less than 6"). Aggression from chemical warfare (allelopathy) could be the ticket>
feed him zooplankton and little cut up food but to no avail it seems....I wondered if he needed more light.  
<might help... but not a quick fix>
I sort of moved him around a bit in the beginning when I first had him but then I thought I'd better stop....
<yikes!!! For some coral, 2-3 moves in the first week is all that it takes to kill them. It is very stressful and drains their reserves trying to adapt. Please (!) put a coral in place the first time and let it adapt no matter how it looks... moving it won't help>
nothing seemed to help and I thought that I should leave him alone..
<agreed>
He is mid tank in our 75 gal.... not near anybody....not happy...Thank you for all your help....Helene
<alas... no clear cause either. Do keep feeding, improve light and have hope/patience. Anthony>

75g Reef Tank Lighting/Coral Level Question  - 2/15/03
Hello,<Hey there! Phil here!> I am a saltwater aquarium Fan of 1 1/2 years with the tank I have now. I have had a saltwater tank before (back about 14 yrs.)  I had crushed coral on the tank's floor, No Living Coral, Dead Coral rocks stacked for hiding spots for the fish. I had clown fish, anemone (i tried to keep them), & I had for just over a year one pair of Seahorses. (When I bought them POPPA was not far from Delivery Day.) I asked the shop owner that I bought the horses from If I would need a nursery tank for the young horses & I was told NO THE young HORSES would find hiding spots & nothing I had already would eat the young. Yes, I bit on that info & about 10 days later POPPA HORSE started delivery for about 1 1/2 days. I lost all the young in 2 days.
I now have a 75 Gal tank with an EMPEROR Dual Bio-wheel Filter System, A 48" 100Watt high output compact Florescent strip light, The light system is on a timer that is on roughly 11 1/2 hrs.
I have Fish wise 1 Yellow Tang, 3 Common Clowns, 4 Blue devil damsels, 1 Goby (not sure on species), 2 flame scallop. I also have 1 pink tipped anemone
I have in the area of LIVING Coral; 1 candy coral, 1 Open Brain Coral, 1 Bubble Coral, 1 Colt Coral, & 1 Frogspawn coral. Now I have a Orange Tree Gorgonian also. I'm not too sure what class to put that.
Now I am not sure if one type of coral goes HIGH LEVEL, or mid range, or LOW range (meaning setting in the sand or on the sand or a couple inches off the sand). My highest point of coral is about 7" under the waterline. I have the Open brain, Bubble coral, Colt coral, Frogspawn coral sitting on the top level of the coral. My Candy coral is about 4 1/2" from the bottom of the tank. My Orange Tree Gorgonian is braced in the sand.  I've read that the Frogspawn can shock other Living coral. Is this true? I am planning on moving the Colt Coral to the sand, putting some of its base into the sand, is this GOOD, BAD, or does it matter? Can I put the Open Brain coral on the floor too? My Orange Tree Gorgonian is about a month old for my tank, I have not seen any feathery arms from it at a Day or Night time period. It is also getting a green Algae cover to it. What can I do to help it?
<Well Randy.  I've talked to Ananda and this is what we have come up with.  The corals you have you are going to need a LOT more light!  At least 200 watts, better is 250-300 watts.  The Orange Tree Gorgonian needs a powerhead to create some water movement.  The 4 damsels will be problems in the not so distant future.  Place the corals in this "order":  brain on the sand... colt on the sand... others up on the rock.  To clean off the Gorgonian take a very soft brush and gently brush off and algae.  Keep the coral IN THE WATER!!  You don't say if you have a skimmer, you really should have one!!  They will help keep the green algae levels down.  Also what are you feeding your anemone?  Please see... www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/anemones.htm Give all this a try and let me know how it works!!  Best wishes...  Phil>

Really bad LFS advice (the LFS strikes back... weak) - 2/12/03
Last entry on this topic Anthony, this is the response from the LFS after he read your reply, (Am I stirring it up, or what!);                                                                      
> Ask this guy if he's ever heard of the Ocean.  Ask him if he's ever seen a
> reef before. If he has, as him how they survive in the wild, a few feet
> apart. enough said.  this guy wants your business and your money.  nothing else.
> he needs to get a real job and leverage his fear tactics on someone with
> less intelligence than you. if he can answer your questions in reasonable fashion listen to him.  if
> not, use some practical advise to achieve your own decisions.
hope this helps.
<Dude... I'm not sure if there is a question in here from you or not, please only send in legitimate questions that you cannot answer from the archives and beyond. We have no time or desire to exchange dialogue relayed or otherwise with folks (this LFS) that are so so ignorant. To answer his latest question: yes, I have spent time on a reef... not the least of which was my birth and residence in Hawaii! I also noticed that he did not answer my question if He's ever seen 2 LPS coral 2" away from each other on a real reef. Corals on a reef are not mostly or only feet apart (just the competitive species that he is recommending you keep 2" from each other!). Many others touch... but they are conspecifics. I also notice that he seems to be glossing over the fact that we are unpaid volunteers here at WWM but he is trying to sell you corals among other things. And what's up with his lame cheap shot at me/us at WWM to "get a real job". Are we getting persecuted for volunteer work that improves the industry that he makes his living in? Or does he think the only way he can make a living is by issuing bad advice that kills animals? Do me a favor... tell me what store this guy works at so that I can enlighten the owner or avoid them in my travels. Regards, Anthony>
[Editor's Note: it is also worth pointing out that reefs see an influx of hundreds of millions of gallons of water each day, sometimes as frequently as each hour. Comparing a closed system of any size to a wild reef is a big mistake.]

Really Bad LFS advice follow up - 2/14/03
Anthony, I didn't intend on starting any issues, and will not participate in further comments (except sending WWM the LFS name. hee, hee!)
<No worries, Scott. And my apologies too... I have let myself answer mail while being fatigued as of late from helping to get our new book to press on time (or close to it, Yay!). My answers were very gruff and grouchy and I apologize. But... that doesn't change the fact that the LFS clerk/owner and his advice were not only staggeringly ignorant and flawed... but they were harmful to life. He is killing animals IMO by his advice and profiting from it to boot>
I do believe that retailers that sell us the animals that we truly care for & then give us the advise that does not promote the "pursuit of happiness" these animals deserve, Don't deserve our patronage,
<Exactly correct... rather than try to change someone's mind that doesn't want to change, vote with your feet and your dollars... simply don't support any industry that you don't believe in>
(unless to adopt these creatures into a stable/productive life IE; save their lives!).      
<Ack! No way Scott... the "buying a creature from a bad store to save its life" bit is bad. All it does is kill more creatures by encouraging that store to order another/more for having made the sale! The best thing you can do is leave that creature there (even if it means it will die) so that many after it will not be killed by a bad merchant or aquarist:>
So, with that... enough said. Anthony & all at WetWebMedia.com, I thank y'all from the bottom of my heart for being... uh... YOU!                                                  
<Heehee... and thank you for putting up with me <G> >           
PS. The green finger you helped me learn to the "mash 4077" surgery on is looking great & standing proud on the coral rubble it attached to! (and there was great rejoicing!) Thanks again, Scott in Denver
<Best regards, Anthony>

LPS alert - 2/8/03
Hey Gang, <Hey Scott.>
How ya be? <I be Paul, and doin' good> Well, I trust! <Well as can be> I picked this coral up today for $28, it's about 4"x3" with intense green colors.<Looks like a Trachyphyllia geoffroyi. A very beautiful and hardy LPS coral after proper acclimation and a regular feeding regime of 3 days a week minimum or more if needed. More never hurts in my book. <if it will take it)> I placed it about 8" from the 65 watt pc lights. Is there any quirks associated with this kind of animal? <Oh? You didn't check its needs and requirements before purchasing? I guess can't always have the foresight being that these corals are soooo beautiful. <G> Here are some links to start you studying':
http://www.wetwebmedia.com/trachyphlliidae.htm
I would recommend placement on the substrate away from rocks (it will inflate) and being that it will readily accept foods (fine chopped meaty foods i.e. Mysid shrimp of the frozen variety, other frozen planktonic foods (krill) et al) I would feed it at least every other day. A good idea to keep other corals from touching this beauty as well. I think you find a great deal of information about this coral in the link above. Quite a bit is known about this species of coral. Even breeding in captivity is being discovered. Do wish you good luck. Search everywhere and anywhere you can!>
The other corals are a toadstool leather, various 'shrooms,  finger coral & a Kenya tree. Will the new arrival have a problem in a "soft coral" tank? <With the corals listed? Probably not, but in any case give room where you can between corals.> Thanks for the help.
Scott in Denver
<My pleasure. Keep in touch. A nice addition indeed, Scott>

LPS alert 2 - 2/8/03
Thanks for the info, Paul. <It is truly my pleasure, Scott> I just moved the new piece onto the substrate before I checked the email! <Very glad to here that. Abrasions equal doom for most of the Open Brain species> Your right I should've done some homework on this type of coral, but, as you said- it's to cool. < So hard when in store and you see something that is a must have. Just don't want to have to walk away with the possibility of it not being there tomorrow. Even with good intentions though, better to give it the best chance it could have by doing a little research. I applaud the fact that you did find us and seek our assistance. A first step at research and responsibility.> I wasn't gonna buy anything, just went to "check" out the store..& next thing I know I'm taking it outta the store! <Totally understand, and by the way, that is how I ended working here. One step at a time, next thing you know your knowledge is being put to the test for all to see and either benefit from or criticize. Very scary but an honor just the same! Keep researching and learn all you can, Scott. I applaud your efforts> Thanks for the info!!                                                       
Scott  
<Any time!>

Coral aggression
Surfs up guy!
<OK... but I'm still not going in... you can be shark food if you like>
I'm curious as too how to tell which corals are aggressive and which are not.  
<easy... all of them. None can touch and most will fight sooner rather than later. Preservation of the species as it were. This is a common underestimate by aquarists that place corals close to each other and it then takes a year or two before they shed enough poison on each other or touch to cause fatalities (allelopathy). The bare minimum distance for the 1-3 year plan is 6-10" in between. Even this is risky with some species>
How does one know what corals don't go next to each other and what not?
<this is best addressed by not mixing corals from very different groups in the tank. My advice is to specialize at least somewhat: octocorals, LPS, SPS, etc>
thanks, Jason
<best regards, Anthony>

Caulastrea bouquet
Hi I'm just wondering if various Caulastrea colonies (aka trumpet, candy cane, etc.) will sting each other or whether I can safely place them in multi-color bunches. Thanks in advance! Adam
<they cannot be blended in a bouquet and service long-term, my friend. These "colors" are different species and intolerant of each other. Aggression is not always apparent for the first few weeks/months, but one or both colonies will suffer in time. Best regards, Anthony>

Re: your information
Your crew is really working great for you!!!  You've trained them well..  Get to the point. If you are really into this to help people with there systems or to answer or help with there problems then encourage them to buy our book.  But you's seem to by pass the help or the point of all the articles that are sent to you.  With stating they need to buy your books.  I had an order placed until after 2 days when I finally got a reply from Craig and every other sentence was a worry and then buy this book of yours. Never an answer to my questions..
<Really? Unusual. I don't read all, but I do place most of them on WWM. But I see below that Craig actually did respond, try to answer your questions, referred you to our (free) site...>
Well as you know this is a vast world of information out there by many good bio's and I really think you need to look at your marketing poise and consider them.
<Umm, didn't think we had "marketing poise". And, in fact, we don't have any training... not formal... none. We ask that the folks that help us answer as well as they can, or send the queries to someone else on WWM...>
  Believe me when I say this I have 24/7 to chat and go around all aquarium sites, stores and this is the buzz!!
<What?>
Sorry this isn't a good one that you can publish.
<We publish all>
But business people are business people with out u's and I's  in  (bsness) business their is no such word.  Thank you for your time in this matter I will also forward my questions and Craig's reply  
David Demers
<All right. Thank you, Bob Fenner>
Picture of 75 gal
90 lb live rock
50 lb live sand
Eheim wet dry pro canister
tech 5 hang on filter
red sea Prizm skimmer
powerhead 802
powerhead 402
coral SeaLife power compact 48" 2 96watt 10k day 2 85k actinic.
Quick over view of what you see starting from left to right
from top down.
purple sea whip 2pcs.................bottom left
pulsing white xenia 3 pc sm....... top left
open brain metallic green lg........next bottom left
button polyps sm.......................next top left
umbrella rock sm........................middle left
feather duster 4pc......................misc areas
bubble Anenome lg.....................top ctr rear placed it self
green carpet Anenome sm..........top center
green maxima clam sm..............top ctr frt
star polyp lg..............................top ctr right
flower Anenome lg......................middle ctr
Ricordea sm...............................middle ctr right
curly q Anenome med ................right rear lower self placed
candy coral ..............................right middle upper
flower Anenome med..................right upper
frog spawn med.........................right middle
hammer coral med.....................right lower
orange Gorgonian med................... right side
flower Anenome med..................right side lower
I know, what do I want?  Tell me if from what you see positioning of all this ok if not please let me know what to move and where.  Every thing is doing very well!!  Tank is 2 months old I change 10% water weekly watch calcium, kH use a-b buffer (Kent)  ph ammonia ph.  I have a good clean up crew and 5 fish 1 tang, 1  6 line wrasse, 1 mandarin goby, 1 maroon clown fish, 1 antenna goby. I feed an array of frozen, freeze dried, canned foods and zooplankton ,micro food marine snow.  Please let me know how we are doing and any recommendations good or bad.  I know, slow down, but this is all  great to me and my 13 yr old son Kyle who started all this is desire is to become a marine bio.  Thanks for your time sincerely David and Kyle Demers  
ps: Use all coral life products reef energizer-live rock sponge food- vita chem. w freeze dried -Selcon with all other foods frozen silversides fish to anenomes.
<Yeow! Where to begin? PLEASE, for the sake of your inhabitants, yourself, your son, and your wallet, slow down and purchase one or more good books on keeping coral reef invertebrates and marine fish. Bob Fenner's book is an ideal start. Of concern to me is stocking so many different animals from various biotopes. Far too many anemones too soon. Not only do anemones require pristine, *well-aged* systems, they are notoriously difficult to keep and toxic to the rest of your inhabitants when they go. Your Carpet anemone is small now, but if he survives he will easily outgrow the width of your 75 displacing all other inhabitants in his wake and likely eat some of your smaller fish along the way. The others are of equal or greater concern.  The Mandarin requires pods to eat which come from well established live rock. This takes time and can't be done in two months. Maybe start with going to wetwebmedia.com reading the marine set-up and stocking sections. Then type in each inhabit!
ant you have into the google search engine and read about each one and their requirements so you can start somewhere. Everything will "look great" for two months.  Usually this is done in the reverse of how you did it. The system is designed for the desired inhabitants, usually from a similar biotope, the requirements for each are researched and provided for in the design and placement.  Like landscaping. For instance, I can't grow citrus because it comes from a warm biotope and I live in a cold one.  I can grow apples though.
Many of your inhabitants, like the clam, require very intense light and will require higher placement in your system, closer to the light. Please look into the lighting requirements, circulation requirements (up to 20 times tank volume per hour) for your critters on WWM.com.  Also filtration information.  With enough LR and sand you don't need the canister, but right now it could run w/o filter media for added circulation.  I would caution you against using so many additives. This is covered in Mr. Fenner's book which I would highly recommend to you.  Please stick with it, there is much to learn and enjoy, but the guidance of a good book or two is invaluable and will help both you and your son learn how to do it right.  Craig>

Moving mushrooms and Starpolyps
I'm moving my 37 gal reef into a 115 gal tank I just acquired at an amazing price (rich guy, got bored, sold very nice system for $500!).  The new tank came with a lot of nice-looking live rock and hundreds of small, light yellow mushrooms all over the place.
<Hmmm... no such thing as light yellow corallimorphs (mushrooms). At least not healthy ones. These creatures are bleached of zooxanthellae from neglect (aged light bulbs, aged water blocked light from yellowing agents, poor water quality, etc). Some will survive, some may not. All will require feeding to recover>
After browsing through your FAQ /articles I still have some questions and need your expert advice.
1. Is it possible for hundreds of mushrooms between dime and quarter size, all pale yellowish, to be healthy specimens of something?  
<good intuition on your part. These are stressed mushrooms>
This does not sound like mushrooms anyone else describes, nor have I ever seen such a thing in a store.  (Their tank had SG 1.024 pH 7.8 NO3 15 KH 6 when I took it apart, lighting is six VHO bulbs, 3 actinic, 3 white, can't read wattage but incredibly hot, ballast is 2 120V Ice Caps, guy said they were 6mos old.)
<Hmmm... take a good look at the lights... 6 month old lights are already getting too old for coral care (change fluorescents every 6-10 months). If the lamp ends are darkening noticeably, they may be older. More importantly... then pH of 7.8 and the dKH of 6 indicate old water likely that hasn't seen a water change in a long time (no doubt part of the neglect of the system)>
2.  They were out of water for about 2-3 hours during the moving process 24 hours ago (simply too many to keep submerged, though I did keep them wet).  Most look ok, some have brown sections.  Are these likely to die?  
<not that big of a deal... most all can take it. Dying ones are unmistakable... they slough a lot of mucus and appear to melt>
If they are dying, should I remove them?  
<ASAP... could get infectious to others>
(I seem to remember reading something about dying mushrooms producing something terribly toxic, but can't find it
today).  Do I need to run a PolyFilter for a while if a lot of them die?
<indeed... PolyFilters, carbon and water changes will all be very helpful>
3.  The live rock/mushrooms are in a heated, circulating tub in my bathroom while I am waiting for the tank to settle (very fine silty substrate) and generating enough RO water to fill the tank so it can run.  
<understood... be sure to aerate the water before buffering it and then before salting it>
This will probably take another couple of days.  Will they be ok in the dark in the bathroom without significant lighting or am I creating an emergency?  
<nope... food is more important right now for these creatures. If you can do water changes you may feed them a little. Else simply  wait for the tank to be set up>
If this is not ok, what do you suggest in the meantime?
<cheering for the Pittsburgh Steelers today>
4.  Non-mushroom question:  I have lovely green star polyps growing all over the back of the tank in my little reef (I like this so much it has made me put off getting a new tank for months!).  When I move out of that tank, can I peel them off and stick them to something (of course I can, but is there
any hope of survival?)
<they will easily survive. The underside of the stolon mat can be superglued to a temporarily dry wall  of the new aquarium (drop water level... glue coral... wait a few minutes and refill). They can also be glued or tied to PVC pipe or anything else you might like. Slashing or nicking the underside of the stolon mat with a blade will also spur growth and reattachment (mentioned in my Book of Coral Propagation)>
or do I just have to let them die?
<absolutely not my friend... they will almost certainly live. Very hardy>
Thanks in advance Tracy :)
<best regards, Anthony>

Corals on the sand
Anthony do you have a list of corals that do well on the sand in the FS they put them put them all over the place in the tank set a bad example.  RGibson
<hmmm... good question. No, my friend- I do not have a list but it is a very good idea for someone to make one. It is actually pretty obvious with a little guidance by looking at the underside of the skeleton (corallum). Free-living corals are rather conspicuously shaped. If you or any daily readers feel frisky, perhaps use the last 2 works by Veron as a good foundations to browse through and make a list (he categorizes the species as free-living or not). And report back with a short list :) Best regards in the New year! Anthony>

Open brain and plate corals on sand
Thanks for all the info you have on your website, great source of info.
<our great pleasure>
I have a question concerning the placement of my open brain and plate corals.
<easy... on the sand <G>>
I have them both on the sandy bottom and they both are doing good.
<indeed... it is their exclusive natural environment>
I recently added a redlined sandsifting goby which while sifting sometimes deposits his mouthful of sand on top of one of these corals. Should I be concerned with this,
<heavens no, my friend... this is natural occurrence for the plate coral especially which brings food in the process. Less so for the open brain (more flow needed here but still not a biggie... rather nutritive)>
the water flow is moderate so the sand is not washed off by current my understanding is these corals do not like strong current?).
<Hmmm... not strong by ocean standards... but tolerable by our weak aquarium conditions. Give these corals moderate random turbulent flow so that sand does not sit on them for more than a couple of hours>
I also understand placing these corals on the live rock is really a option.
<no way... I disagree. Neither Heliofungia nor Trachyphyllia are ever found on rock... they are always on sand. I am nearly certain that the plate coral will be dead if placed on rock in well under a year. The brain is more forgiving, but most suffer within 2 years (lack of food from sand absent, abrasive polyp cycles on rock, etc). The problem isn't the corals... its the weak flow and the repetitive activity of a sand sifting fish in the unnaturally tight confines of the aquarium>
As always your opinion is appreciated. Thanks
<we're grateful that you care to know our opinions. With kind regards, Anthony>

Coral placement (Plate Anemone Coral)
Hello, I have a Heliofungia actiniformis placed about 8 inches below a Euphyllia ancora.  Both apparently healthy with skeletal growth and extension.
<hmmm... is the Helio on the sand bottom... must be to survive long term. They are free-living corals and will suffer if kept on rock and likely die within a year or so>
Lately the Helio. Has extended its tentacles towards the Euphyllia (only towards this coral, all other tentacles remain similar previous length). Is it "targeting" the Euphyllia?
<indeed... quite possibly modified sweeper tentacles in defense of the very aggressive (tentacles and allelopathic secretions) ancora Hammer coral>
If so, do you have any personal experience with placement of these species you could share? Best, Michael
<popular thinking is 6-10" for non-aggressive species, 10"+ for aggressive. Be sure to feed both (especially the Euphyllia) very very fine minced meaty foods 3-5 times weekly for long term success. Best regards, Anthony>

Unhappy hammer- coral aggression
My hammer coral was looking good until I placed a purple torch next to it. They were about 2.5 inches apart, I increased the separation to ~4 inches.
<very good move but not enough. The "rule" is 6-10" minimum between all coral... more between aggressive species. These two coral mentioned are VERY aggressive (modified tentacles at night and chemical exudations shed>
The hammer's polyps are semi-retracted, sometimes completely retracted. Both corals are stetting on rocks on the bottom of a 29 gal tank. I've had the hammer for about two months, everything was fine, its been about four days since I got the torch.
What should I do?
<more space and good water flow. Aggressive skimming and weekly changes of carbon will help temper the aggression too. Best regards, Anthony>

10 year old Gorgonian... battle with Colt coral
I jinxed it, no doubt, because now, it has mostly pulled its polyps in, and all I have is the bare gorgonian branches.  
<bare as in denuded of tissue (rotted away)? Or are you simply referring to the lack of polyp extension (no biggie here)?>
Other than being bare, the branches look fine.  The other inverts (Tridacna, star polyp, colt coral, shrimp, brittle star) look fantastic.  The water parameters are still great. However, the gorgonian had been in contact with a colt coral.  
<Yikes!!!! Very bad for the gorgonian... Colts are wicked. Will take some time to recover. Keep up good water changes and strong water flow. >
Although I can see where that might have caused problems, I am surprised at the timing, because the two had been touching for several months, with no apparent effect to either one.  
<you are completely mistaken here my friend... it is precisely the prolonged exposure that creates a situation like this. Keep in mind that corals must war chemically and silently. They have no teeth or claws, can't throw a punch, etc. They just shed noxious chemicals over time to slowly poison each other (and themselves in some cases)>
I did a water change, carefully removed the colt's
rock from the tank and equally carefully removed the coral from the rock and donated it the colt to my LFS.  
<actually a fine idea. Colts are beautiful... but they are one of the most severely noxious corals for aquaria!>
That was yesterday.  The gorgonian tried to send a few polyps out, but overall a fairly substandard performance.  
<no worries... all in good time. Weeks perhaps>
I seem to remember something like this a few years ago with it -- I thought at that time it may have "shed" like the colt coral does from time to time.  
<you are correct my friend... a waxy tunic of metabolites>
Also, where one branch has grown against the front glass, the polyps don't come out and that small piece of branch looks a little "smushed"  
<yes... it has formed a callus likely>
On the chance that this area needs some water circulation I am going to rig a way to keep it from touching the side. Any ideas/advice?
<I'd simply propagate/prune the branch shorter>
thanks for your help, and happy holidays to all! Tom
<and to you as well, my friend. Anthony>

Tang nipping coral
Thanks for your quick and thorough response.  While I have no doubt that the two corals touching was or was going to be a real problem, I think I may have found the more immediate problem.  Yesterday morning, I noticed that the gorgonian was trying to open polyps.  I backed away from the aquarium so the fish could not see me well, and I saw it.  The scopas tang swam over to one of the main branches and actually pulled a polyp off!  
<Ha! That cheeky little monkey!>
I guess it wouldn't have been quite so bad, except that then he spat it out.  Five minutes later he did it again.  
<heehee... er, yes... I do believe you have found the immediate source of irritation. Truthfully, I wouldn't have guessed it. Its funny too... many European aquarists regard tangs as not reef safe. Most Americans do. We might say that 20% of tangs collectively will nip coral. "Reef safe": a matter of perception! G>>
Even though he had been in the tank with that coral for 10 years and never bothered it, I had to trade him for that
>transgression.  My LFS was happy to take him off my hands for "creature credit."  Also, I thought he had gotten too large for a 45 high tank, and he had started to like all too well the taste of meaty foods (all foods, actually, but especially the food meant for my slower mandarin!).  
<agreed on all counts>
Here's the nifty way I caught him without disturbing the reef.  I submerged a thin plastic food storage bag in the tank, with the bag rolled over like for use as a garbage bag.  After the tang had gotten used to it, I then used my standard feeding pipette, and fed the tang at first near the bag, then inside the bag.  Greed overcame caution, and he followed the food into the bag.  I closed the top, lifted it out of the aquarium, rebagged into a tougher fish bag, rubber banded the corners, put it in the cooler and took
it downtown.  The capture took about 5 minutes.
<very crafty, my friend... will be posting>
I would like to replace the tang with a smaller, colorful fish that won't hassle the mandarin, clam or the corals.  Do you have any favorites?  I was thinking of a pajama cardinal perhaps... Thanks for your help. tom
<indeed... the cardinalfishes are very fine. Some wonderful fairy wrasses and Firefish too (Helfrich's Firefish if your taste is expensive... a phenomenally hardy and beautiful fish). If you keep this tank peaceful, perhaps some sunburst Anthias... one of the few hardy and small species. Gorgeous. Best regards, Anthony>

Coral Placement
Anthony, thank you.  Yes I am running MH's - 175W.  But the coral is 2 1/2 to 3' below the lights.  
<wow... too bright for most LPS in less than 10" of water under MH. Very fine for most SPS and many soft coral though. More importantly... this species lives on sand and must be kept on sand>
And yes, there are 2 open brains within only a couple of inches from this guy, which where far, far away before I moved him.
<indeed an explanation for the mesenterial filaments. To insure health and growth of all corals, place no two species closer than 6". Most experts actually say that number should be more like 8-12". I'm inclined to agree because we are keeping our corals (like a cat, dog or anything else) with the expectation that it will life a full lifespan in our care. As such... a couple of years down the road they need a lot more room to grow>
So I should put open brains and this guy in the sand eh?  I had no idea.
<yes, my friend. Necessary here for several reasons>
Thanks so much...Steve
<Do invest in a good reference/book before you buy another coral. And please research each living creature you intend to keep before you buy it to discover its needs. In this case... consider Eric Borneman's "Aquarium Corals": excellent content and pictorials. Also, my "Book of Coral Propagation"(450pp) has almost 200 pages just on the fundamentals of reef husbandry as well as a coral family overview that describes every popular coral in the trade and their requirements. You will really need my book to prune corals if you keep placing your corals mere inches from each other, my friend <G>. Kind regards, Anthony Calfo>

Reef Questions
Hi, Not sure whether you remember or not.  I write before asking how I can save my sick Powder Blue Tang.  Thanks a lot for your reply, I did successfully saved it and it now seems very healthy.
<awesome... good to hear!>
But another problem arise again.  While I thought PB Tang is reef safe, the one I got didn't seems so.  It is eating my Clove polyp (the one mentioned in Julian Sprung's Corals: A Quick Reference Guide p. 149).  
<this certainly isn't uncommon. In European reef books, tangs are listed as Not reef safe. They are indeed nibblers. Usually not too bad though>
My LFS says this is unlikely but I'm quite certain since I actually saw it eating it.
<Oh, I believe you! Have seen it myself>
And with just one day, it almost completely eaten all the clove polyp.  Now the clove polyp is in a separate container and seems recovering.  The tang also sometimes nip at my other soft corals.
<and it is going to continue to no matter how well you feed it. Natural. This specimen must be removed>
But other corals seems less affected.  Is there any way I can keep both the tang and the clove polyp?
<yep... separate tanks>
Also, from what I read, corals should be put from each other at least 6 inches apart, better to be 1 feet apart.  
<correct for long term growth: 3-5 year plan, to spare you from having to prune/propagate and for optimal coral health>
So, my tank is now relatively lightly stock with soft corals.  However, the feature tank in this month www.reefkeeping.com
(http://www.reefkeeping.com/issues/2002-11/totm/index.htm) is quite densely populated.  Was he doing a wrong thing or his corals are carefully selected that are compatible with each others?  
<nope... like any aquarist that succeeds this way. These corals need constant pruning, have extraordinary water quality (skimming, ozone or carbon, string water changes etc) to control chemical warfare, and... least glorious of all.. suffers occasional and random "deaths" of corals die to the unnatural cording, allelopathy, etc. Still a successful aquarium overall, just not realistic for most aquarists that don't want a second job... just a hobby :)>
Grateful for your advice. A final question (sorry for asking so many questions).  I'm now changing about 2% water every two days.  If I keep this practice, can I avoid monthly or bimonthly large quantity water change (say 10%)?  Or it still helps if there
is a relatively large water change occasionally?
<let your water chemistry determine that. If numbers are low and health looks good... continue to enjoy your 2% daily changes>
Thank you very much for answering my questions and your site is really a great treasure to us. Regards, Manus
<thanks kindly, Anthony>

Coral Compatibility Is it O.K. to have these pulsing xenias this close to these green star polyps. <not in the long run... perhaps not in the short term (weeks) either. Starpolyps are noxious and aggressive> I think I read that the green stars might produce toxic chemicals. <they are one of the most aggressive corals in the hobby> Also is it O.K. to have this Kenya tree coral next to this piece. <no two corals should be allowed to touch ever... all will fight in time> I think someone on your site said it might be a Sinularia species. <it may be... tough to tell form the picture. Best regards>

Coral Compatibility
Is it O.K. to have these pulsing xenias this close to these green star polyps?
<in the long run, it is not safe to let any corals touch. One will surely sting and kill the other colony. It may take days, weeks or months... but it will happen. Starpolyps are actually one of the most aggressive of the commonly imported coral (they don't look it but they are extremely noxious). Avoid letting them touch indeed>
I think I read that the green stars might produce toxic chemicals.
<an understatement>
Also is it O.K. to have this Kenyan tree coral next to this piece.
<again... no touching of any species>
I think someone on your site said it might be a Sinularia species.
<by the photograph I would agree. Kind regards, Anthony>

Saving a Hammer
My question is to whomever can help with this issue. My Hammer coral fell on my Galaxea today and it doesn't look good. Is there anything I can do to possibly save it? Thanks
<be sure the Hammer coral is returned to its exact former place, set securely (use underwater epoxy if necessary), maintain very good/strong random turbulent water flow, add small daily doses of iodine to the water (regular weekly dose just fractioned for daily application) and observe carefully for necrosis or infection in the tissue. Extra water changes may be necessary to reduce mucus shed from stress. Best regards, Anthony>

Torch Coral (Euphyllia glabrescens) placement
I have a question about lighting requirements for the torch coral.
Since placement on a sandy bottom is preferred, 
<placement on the sand bottom is neither preferred or recommended. This Euphylliid occurs only on hard substrates in the wild and will suffer if forced to purge sand deposited by sifters. The confusion may stem from the fact that such coral care best often in the bottom 1/3 of the tank under metal halide lights. Indeed... they do not like or require extremely bright light. They do however need weekly feedings with fine minced meaty foods>
would it get enough light in an 20" tall tank even though I am only using 2 96 watt 10K power compacts? Thanks
<it may not get enough light here, but you can compensate for the lack of light to some extent with extra feedings (weekly instead of a few times weekly). Best regards, Anthony>

RE: Torch Coral (Euphyllia glabrescens)
Elegant Coral
Anthony,
<cheers, mate>
I think I may have been confusing Euphyllia with Catalaphyllia (elegance), this is actually what I wanted to know about. 
<ahhh, yes! You are correct my friend. Indeed they fare best on the sand bottom. The exception in the Euphylliid family>
Can they thrive in low light conditions on the sandy bottom of the tank? My bad.
<no worries... and yes, indeed they can thrive at the bottom of the aquarium. Especially if you have the purple tipped variety which is often indicative of a specimen collected in rather deep waters (60-80 feet down). The key to keeping elegant corals successfully is frequent feeding with very fine foods. They are one of the hungriest coral. If fed almost daily with small bits (never offer larger than 1/4-1/2 inch although they will take it), they will thrive and grow nicely. Your lights will be fine for this coral on the bottom of a 20" deep tank. Help all along with weekly water changes, good skimming and weekly changes of small amounts of carbon to maintain great water clarity. If you haven't read it yet... see here:
http://www.wetwebmedia.com/fdreefinverts.htm
and here:
http://www.wetwebmedia.com/marlgtganthony.htm>
Thanks Angelo
<best regards, Anthony>

Injured Chromis, Carpet Anemone, Corals
Hey Guys salutations!....
<Salute!>
I have a 150 gal reef tank with 3 Maldives clowns, 2 carpets, various SPS's, a school of 8 Chromis, and an Asfur. Today I noticed one of the Chromis' having one side of its scales ripped off by its gills. Its still active and eats with the school but is it a disease of some sort? 
<tough to say but unlikely... if so it may be quite a condition. Fears here of a Septicemia. Without a clear photo were speculating here>
The Asfur does magnificently disperse the school periodically in a fit of rage but I have yet to see him actually nip at one. 
<statistically he'll succeed one day if he hasn't already...Ha!>
My other thoughts are that I have lost 2 Chromis' to the carpets, I guess they stupidly float in there at night or something because on the afternoon after the disappearances my carpets spit out a meatless carcass of bones that suspiciously look like the frame of the Chromis.
<indeed>
Could this particular Chromis somehow brushed the side of its face against the carpet causing some blisters? 
<possible... but carpets are so potently aggressive I would expect a kill>
Everything seems normal, but I will make a water change today just in case. Give it to me straight...thanks!!!! 
<OK... separate the anemone and other cnidarians (SPS corals and the like)... its a long term recipe for disaster (3-5 year plan). Noxious chemical warfare and the motile nature of the anemone>
Oh yeah any good clubs to join in the Los Angeles area?
<Absolutely... MASLAC at http://www.maslac.org/ I'll be speaking there in two weeks :)
several other clubs in neighboring areas... SO CAL reefers, San Diego, etc>
Regards, Dennis
<best regards, Anthony>

Coral competition
<Anthony Calfo in your service>
I have a few questions regarding competition for space in my aquarium. Which coral will win out over all for the space between an SPS coral growing next to a colony of polyps? 
<cannot be said in fairness categorically as each species is different. But in gross terms, Zoantharians (mushroom and zoanthid button polyps) are VERY aggressive and will often tame SPS corals. However, please do remember that corals forced to live close and combat are not necessarily win vs. lose. Sometimes both will suffer and or die after many weeks or months of being forced to compete>
The polyps are zoanthids and the SPS coral is an Acropora that is growing branches. The Acropora is spreading out at the base as usual, but it is getting close to the polyps. 
<hard to say for certain... the rule is that no coral should be allowed to touch. Please frag the Acro to tame its growth or consider a "firewall" of rock/rubble for control of either animal. More about this in my book on coral propagation. Please do advise me if you need excerpts>
I also have 2 small SPS corals that I glued onto the same small rock. Well as you can imagine they have both grown into fine looking specimens; 
<ah, yes... a common problem>
however the base of one is growing onto the base of the other. They are both great looking corals and I do not want to break either of them off. What should I do? 
<they need to be separated. Even when they appear to be getting along, one will die "mysteriously" after some months from the silent chemical warfare>
One is a brown and white Acropora with a thick base and thick branches. It's base is being grown onto by a Montipora capricornis. The Montipora is growing into whorls and looks awesome. Which will win the fight? 
<the Montipora is going to get smoked like salmon by the Acropora...heehee>
Any advise? 
<yep... buy a bigger tank, add a refugium for frags, place corals with consideration for long term growth/adult size and/or be more willing to frag corals to control growth of close specimens. Best regards my friend, Anthony Calfo> 
Thanks!!

Chemical warfare
Hello , will my Goniopora (flower pot) and my anemone wage chemical warfare on each other? 
<yep... and I'd bet good money on the Goniopora losing the war in the long run>
Because it seems that when the flower pot is open and happy the anemone is upset and retracted and vice versa. 
<very good of you to notice...seriously>
Sorry I know these are two specimens that you don't advocate buying, but hind site is always 20/20!
<no worries... I have already FedExed a dead snail to your location for someone to place into your locked car on a very warm day with instructions to roll up the windows>
My tank is 135 gallon with 40 gallon refugium 180 lbs LR, 5 inches LS
assorted corals and community fish and inverts all parameters are perfect (sorry don't have them with me or I would pass them along).
<just knowing they are "perfect" is enough without those bothersome numbers...hehe>
If this is the case (warfare) will they learn to get along or will one have to become store credit?
<ehhh... most all cnidarians will wage some sort of warfare. Some are worse then others. Most are intolerable in the big picture without aggressive protein skimming. chemical filtration and water changes. My advise beyond that is keep them far away from each other, conduct more frequent water changes and carbon changes and continue to observe>
Thanks again in advance: Joe who wishes he could snorkel in his tank
<Always welcome: Anthony, who does (snorkel in his own tank... not Joe's>

Care of Open Brain & Frogspawn
Gentlemen,
Thanks for answering this question in advance. I just purchased an open brain and a frogspawn coral for my 125 reef. I have a 6 foot 175w 10,000k halide w/ VHO actinic setup. Live rock and DSB. Everything in the tank has been great. Here are my questions about both corals. I read your articles on WWM and still do not know what is the best placement for these two?
<Both light moderate light, not directly under you halides, off to the side and in the bottom half of the tank.>
Is it in a high-flow area, well lit?
<Moderate to strong flow, but not directly on either. No LPS's tolerate direct flow.>
I was told the brain likes to be on the sand in front?
<It actually needs to be on the sand.>
I have about 2000 gallons/hour flowing through the tank, so
I have mostly high-flow areas. Should I find a low-flow area?
<A lower flow area.>
What would you recommend feeding and how often.
<Mysis shrimp or plankton several times weekly.>
I bought some DT's Phytoplankton, should this suffice?
<Completely useless for these two.>
Let me know how you would care for these great corals.
Thanks! Adam
<You are welcome. -Steven Pro>

How Close is Too Close?
<<JasonC here, Bob is away diving>>
Can yellow Sarcophyton touch LPS corals elegance, hammer etc. or will they sting one another. <<The Sarcophyton would probably come out on the short end of the stick on these battles - elegance, hammer, etc - all have sweeper tentacles which can extend the range of the coral two to three times the size normal polyp length. These corals need a wide berth - more material at: http://www.wetwebmedia.com/elegance.htm >> 
I heard that leather corals may release toxins as a defense mechanism.
Any advise would be much appreciated. <<they do, but there are others more toxic than them. My advise is to not pack any corals too close together unless you are very familiar with their habits. Once you've had them for a while, you will understand better their motives. More reading on their phylum - Cnidaria: http://www.wetwebmedia.com/cnidaria.htm >>
Thanks,
Mario
<<Cheers, J -- >>

Sarcophyton woes
Hi Bob!
<Anthony Calfo in your service>
I have had a toadstool leather (appears to be Sarcophyton
trocheliophorum) in my 55 gallon tank for about 2 months. It has been
happy and healthy as far as I can tell, in fact it is looking better
than it did at the fish store! I recently noticed white spots on the
trunk. Some are smaller than a dime and others are larger and more
oval. I have used a turkey baster to blow off some loose skin in the
area, but these spots appear to be spreading. This morning I blew off
some algae that was growing at the base and underneath it the trunk was
completely white. I took it out of the water and gave it a smell test
and everything smells fine, no rotten egg smell. 
<and the tissue isn't necrotic/eroding?>
I also noticed that the white spots appear to turn light brown, and I can blow this off to reveal the white spot underneath. There aren't any of these spots on the top of the coral and the polyps are opening fine. I have read all my books and searched the internet, but I can't find anything that really describes this. 
<could be the equivalent of a mucosal tunic (shedding/sloughing waste compounds through growth)>
It does not appear to be moving across like a
front, nor it is it moving rapidly. I noticed the first spots probably
about 2-3 weeks ago. Each spot appears to be an isolated spot. Nothing
else in the system is affected. Here's the lo-down on the tank:
55 gallon with wet/dry filter, replaced bioballs with live rock.
4 55 watt PC's 2 actinic 2 daylight
Ph 8.2
NH3 0
NO2 0
NO3 <5ppm
KH 7-8
Ca 400
<do get your Alkalinity up higher...your at the bottom for reef invertebrates...aim for 11-12 dKH>
Livestock:
2 cleaner shrimp
3 peppermint shrimp
1 yellow tang
10 blue leg and scarlet crabs
10 astrea snails
1 serpent star
pulsing xenia
Sarcophyton elegans
Trachyphyllia geoffroyi
2 hairy mushrooms
5 red mushrooms
2 unidentified encrusting corals
The open brain sits directly under the leather in question, probably
about 5 vertical inches between them. Could there be any chemical
warfare going on? 
<Wow! An important factoid...yes, in fact beyond allelopathy (chemical warfare) you brain can easily reach your leather in the dark of night. You may simply be looking at the mucosal symptoms of burns from the brains night tentacles>
The 2 cleaner shrimp have also taken to hanging out
on the underside of the leather, could they be picking at it while I am
not looking? If I move this coral into my quarantine tank, the lighting
in that tank is way low. I think 15 watts regular florescent on a 10
gallon tank. Will this be a problem? Will the shock of moving this
coral do more harm than good?? 
<yes... please move the brain or leather laterally instead (not higher unless gradually. Your brain is stuck in the sand bottom isn't it? Otherwise, there is a very good chance it will die within the year on rock placement>
Help Bob, what do I do??? Thanks Leslie
<an easy solution. Happy reefing. Anthony>

Coral Placement
Hello once again!
<Hello, you reached Steven Pro this time attempting to fill Bob's rather large shoes.>
I have a question about coral placement. First of all, my tank will have 4 N.O. 40w bulbs, two 9325k and two 10000k lamps. The questions I have on placement are: I hear in a 55g with this
lighting, the corals should be placed no deeper than about 10" because of light penetration. So, for a open brain that should usually go on the sand, or a bubble for instance, how can this 10" be accomplished?
<That is a good rule of thumb, but you also need to consider that fluorescent lamps are brightest in the middle of the tubes and get weaker at the ends.>
My DSB brings the sand level up to about 16", but that is still to deep. Can corals such as bubbles and open brains be placed on the rock without damage?
<I would prefer you place the open brain on the sand, but I have placed bubbles in the rockwork.>
Also, how should an open brain or bubble be positioned on the LR?
<You want to position it so that none of the tissue on the skeleton is rubbing any other rocks and that the coral is secure and will not fall over. When they do fall over, they always land tissue side down.>
My other coral q is, how far should the bubbles and open brains and other LPS be far from other
corals?
<This will depend on the tentacles and individual species aggressiveness, but more room is better.>
I am thinking about 6" radius of the coral.
Also, want corals can be placed relatively close to each other without damage?
<This varies greatly be genus and species. Borneman & Puterbaugh's "A Practical Guide to Corals for the Reef Aquarium" is a excellent, simple to use reference. ISBN # 0-945738-99-4 Published by Crystal Graphics>
How much room does a colt coral need around it?
<I can give you one tip on this. You want to try to position your colt coral so that your current will sweep away from this coral and towards your overflow and/or skimmer. Colts exude a lot of toxins and slime that can damage other corals, so placed them "downstream". I too have a 55 with 4-40 watt lamps. You can see some pictures at http://www.pmas.org/feature.html This should give you some ideas as to what will grow under normal output lights and how to position the corals.>