Zoas slowly dying off

[bluwtr]

STrout gave me some frags of zoas from his tank several weeks ago. At first they were all doing great--opened that day and had great color. Here lately though, a lot of them are slowly just wasting away. Almost like they died and the tissue is just being blown away by the current. Now, I have other colonies of zoas and palys that have been in the tank for a long time and are happy as can be. His tank had MH and mine had T5's (using MH+T5 now for two days). I noticed them starting to die last week.

My readings are pH 8.3, Ca 440, Mg 1335, Alk 205.4/11.5/4.1, temp 80, SG 1.024. Everything was dipped in Coral Rx and temp acclimated which is the same procedure I use for all corals.

The only other thing new to my tank are two HK1050 that I added. Could the current be too strong for them? They do seem happier on the bottom.

All help appreciated.

[Amphiprion]

Unless the water motion is focused and forceful, I doubt the water motion is too high. The T5s could potentially be to blame, as it seems to be easier to damage corals with them. That makes acclimation under T5s all the more important. If you've ruled out placement and micropredators/parasites, you may also want to investigate potential infections and treat accordingly. A shot in the dark, I know, but it may be worth trying on an individual piece. I've never treated zoanthids for any sort of bacterial, fungal and/or protozoan infections, so I have little advice beyond that, unfortunately. It may be worth clearing/excising dead tissue and dipping in something germicidal, like lugol's or dip more aggressively with the CoralRx you already have. A last alternative would be use a medication with a strong, broad spectrum antibiotic/antifungal ingredient--nitrofurazone comes to mind and a few folks seemed to have reported some success with it. Again, not sure on the specifics on that, as I've never actually dealt with it, except with disease treatment of fishes.

[bluwtr]

Thanks for the ideas Andrew. I'm not sure it would be the lights because the tank they came from had MH and he had higher PARs etc. However, he gave me his MH because he is going to LED's and I'm now acclimating my tank to them (adding 15 min a day). None of my other Zoa's are showing signs of anything but growth. Another odd observation is that a couple of the frags are doing fine. They are purple while the ones seeming to have the most trouble are orange and green, but I've got some orange and green ones already that are fine--go figure. When I mix my dip I always mix a little higher than recommended just to be safe. For me it seems to actually make the corals open faster. I did move the frags back lower in the tank and they seem to be happier, so it could just be my bulbs are hotter (PAR wise) than his were. I do know his bulbs needed replacing.

Thanks for the suggestions.

[Amphiprion]

Not entirely sure why (though I have some idea possibly) T5s seem to bleach things more easily than halides, but that was at least the case for me. Having some of the same corals under 250w of 10K halide only 6" from the water (in an 18x18 square) vs 500w of T5s in double that area, the latter always caused me more issues for me. The halide is most definitely brighter in terms of pure output (especially in certain spots), but I think the broad, linear output of the T5s seems to be the culprit--and the fact that they illuminate from all sides, as opposed to a nice point source. That was just my experience. Either way, glad to hear that they are doing better now.

[bluwtr]

Those are interesting points. Very well could be the T5 dominance, but who knows. Since I just got home and the tank is dark I don't know how they look tonight but this morning they seemed happier still, so maybe it was a combo of light and current (if that bothered them).