Dont you love it wen your fish die?!?!

Well, everything else aside, one cube of mysis is way too much. As an example, I have a 55 with a yellow tang, two clowns, a yellow tailed damsel and a yellow watchman goby and feed about 1/3 of a cube every other day. I also supplement with algae for the tang. The fish will eat until they can't eat any more and they always seem like they are hungry, you'll just have to learn to ignore this. If you drastically cut back on your feedings and do a water change or two, you should get this problem under control.

 

Ok and thank you and I will cut my feedings way down.