HI, I got 4 new angels in my 55g tank on saturday and 3 out of 4 have been very active and eating normally. I had the water tested b4 i bought the angels and everything was fine. Today 8/31/04 i noticed that one of my angels tails is starting to disappear or rot and i saw a little white string on the tail towards the body. Is this a disease causing this or another fish. I have 3 bala sharks, 3 tetras, and 3 tiger barbs, with 2 plecos in this tank. And another angel hasnt been eating is this angel getting used to the water still or is it sick.And one last question is how do u tell if the angels are male or female. thanx for all of ur help.