Candy Cane in trouble...

[troiusmaximus]

I have a three head candy cane coral that was nice and fat this morning, in fact one head was splitting and super fat. I've had it since August. When I checked my tank this afternoon, it's all shriveled and skeletal. My alk seems low @ 8 dkh but my calcium is at 460 ppm which seems ok. My pH is reading between 8.2 and 8.4. Zero phosphate, nitrate, and ammonia. These are using the API kit.

All other inhabitants seem fine so far. Three fish (kole tang, maroon clown, blue green chromis) and 7 corals (an acans, frogspawn, birdsnest, two monti caps, and a rainbow stylophora), and two turbo snails. This is a 55 gallon with a 25 gallon sump.

What could cause this and what do you recommend as a course of action?

 

[troiusmaximus]

By the way, no recent additions or lighting changes.

 

[degibson84]

Hard to tell from the pic but is it potentially brown jelly!?

 

[troiusmaximus]

I took the pic on my iPad camera, it's the best I have. I think it's just the skeleton showing through. The head in the back looks a little better, no brown. I am going to do a water change. Now I'm not so sure about the ammonia reading, I just tested and it may not be zero after all. My temp is also low @ 23.4 Celsius if I can believe the thermometer.

 

[Reef Frog]

These are durable & forgiving corals IME. Sometimes they just pucker up for seemingly no reason. However I have seen them pucker longer term as a reaction to light that's too intense.

 

[troiusmaximus]

Got a new thermometer. It's showing my temp is actually 83.3

 

[Reef Frog]

If that is accurate its too high, or near the edge of what some corals can tolerate with little no room left for error. Keep in mind many fish store el cheapo thermometers can be quite inaccurate. Personally I wouldn't exceed 80F. Plenty of sad stories on RC about tank crashing via runaway temperature.