I have a quick question. I came down the stairs tonight to find one of my 2" Pseudotropheus Socolofi at the bottom of the tank, dead as a doornail. After I fished him out, I immediately checked my water levels. Both Nitrite and Ammonia levels are quite low. I then went back to my fish corpse and noticed that he was very heavy. Scoured his body for any odd markings, as if he was beaten up and killed, but saw none. No discoloration or anything. I even dissected him to see if he swallowed some of my aqarium gravel, but found none. Anybody know the answer??? BTW, I have seven African Cichlids in a 55g tank, all about 2" in length. Any replies I would appreciate.