Help!!

[skinless85]

Went to bed last night and everything looked normal. Woke up today and my zoos, ricordia, and mushrooms looked like they were melting. Temp. and levels were normal and fish, inverts, brain coral, and bubble coral all looked fine. I did a 3 gallon instead of 2 gallon water change today so i will wait and see what happens. I fed my fish a little while ago and noticed my pig of a clown didnt eat and is breathing really hard. My chromis is hovering in the corner which isnt normal but my sixline, hawkfish, and gramma are all swimming normal. what could be happening? I added a Blue Sponge Coral yesterdat but dont see why that would have any effect on the tank. Any suggestions are much appreciated!
29-Gallon Biocube
SG-1.023
Temp. 78.8
Nitrites, Ammonia-0
Nitrates-5-10
Calcium-440

 

[meowzer]

What kind of circulation do you have?

 

[skinless85]

i have the main outlet and a Koralia Nano...i havent moved the circulation for the past few months. The tank has been setup for a little more than a year.

 

[skinless85]

Well my clown has now moved on to a better place. The other fish seem fine but corals are still looking bad except for my candy canes and bubble coral. Is it possible my newly added blue sponge has let off some toxins? it happened overnight after i added it. it is no longer blue but more of a brownish white. It was never exposed to air at the LFS or into my tank after acclimating.