I have a 75 gal tank that i had just turned into a Angelfish tank. i had some BN Plecos in there also. i started to miss the angel fish and then i found 1 with a red like hole on its gill plate.i added mel-afixs did as it said alot of times i would not find the dead fish it just would be gone.so i had a koi left and it was fine sunday then monday i get to looking for it and its up under my anbise plant under the long stem roots of it with my male BN Pleco is eating it.later that night as i feed them a angel is eatting food on the bottom and he charges at it. i only have 2 plecos left in that tank i had a female dead last week . could he become mean after this and is killing my angels. i have check all my water pemters.every thing is fine.its not a new tank and i has been doing water changes about 2 to 3 times a week to grow up the angels.and help out there..thanks alot..:help2: