Favia Disappearing Act

[httorihanzo]

New to posting on R2R, been on my local forum (DFWMAS) for a few years.

I have a healthy 105 rimless reef tank where everything grows very well. Running 8 bulb T5 ATI. Ammonia + nitrites are zero and nitrates are virtually zero. CA runs about 425 and Alk a little low last I checked at 10.0. MG was a little high around 1400 I think (over dosed).

SPS have good color and polyp extension though I have only been into SPS for a few months. I have 10 -15 new pieces that I all have thrived. 1 quick growing chalice and zoa’s that I cannot kill off.

I have had a few favia frags deteriorate super-fast recently. Like overnight fast. They will look great during the day, hungry at night and then half of it will be missing the next morning. I have them on the sand bed in more shaded areas. Frustrating because I am running into really nice favia’s I want but am afraid to add to my tank.

I have a few tangs, pistol shrimp/goby pair, and scooter blenny and there are a couple emerald crabs. Could the emerald crabs be the culprit? Any other thoughts? Really think something is munching on them as the rest of my coral are doing great.

 

[zesty]

hmmmmmmm, could it be that your favia is catching some food at night and then a pesky emerald crab comes by and says "MINE!" and takes more than the food?

Any long reaching tentacles from other corals coming out and stinging? That's the only time I've seen tissue reduction that fast. I had an acan frag that half of it was gone in the morning because of a nighttime feeding coral.

 

[httorihanzo]

I moved to far to the side of the tank no where near any other corals and low flow. (New Gyre is trying to rid my tank of its sand bed) Shouldnt be other corals. I had another one do somethign simular. Oddly enough it seems like my larger favia frags are donig just fine anywhere I put them. Large as in half dollar size. The frags that are dieing off are 1/2 inch.

 

[Catra2030]

Do you feed your lps corals. I have occasionally experienced the same thing. One day the favia is looking healthy, the next day theres a considerable chunk of it gone, only mine looks like something stung it, but nothing around it to do so. I have come to the conclusion that the coral, although appearing to be healthy, is actually hungry and under nourished, and has amputated so to speak a portion of itself for self preservation. Just my 2 cents, but don't be afraid to spot feed some small Mysis or some form of small sized food. Good luck

 

[httorihanzo]

I sometimes will make sure they get some mysis that makes its way in the tank but haven't gone in on coral food. I will definatley be doing it on higher end favia in the future but I have a hard time thinking something isnt eating these guys up.

 

[Typlus5]

Emerald crabs can be suspect. Just banished mine to the sump for his shenanigans. Caught him on a pocillopora going at it into the meat of the coral. Would examine at night to verify.
Any Alk, temp, or salinity swings that may be affecting the chemistry? All corals will react differently to adjustments or excursions.