I have a 90 gallon tank been up and running a month been putting fish once a week and everything seemed fine havent lost a one ...went amd got a glofish long fin and 2 albino catfish and everything still seemed fine I look over at my tank and my long fin glofish is at the bottom and looks like his tail has been eaten are something its gone none of the other look this way ...I have one other longfin ,my tank is all tetra glofish ...im so confused my water levels look good ,steady temps...any idea of my fish did it are if I have a disease going on ...I dont want loose these there expensive fish...have 38 and now 37