out of control

[ollski]

I had a bit of a problem in that I bought a second hand tank and some fish and transported them half way across uk and set up in my house. New water, need to cycle tank with fish, during which time 1 red platy died from high ph (8.5) temp (81f) and ammonia (0.5).We have sorted that and are doing regular water changes now we have temp 78, ammonia 0.1 and nitrite 0.1, but tonight found another red platy dead, only this time he had been half eaten and was being picked at by a sailfin molly when we picked him out. Do you think the fish would have killed him and then tried to eat him and if so am I underfeeding?, we have been told not to feed at all to reduce stress levels or would he have been killed by the tanks chemical balance?

Fish list
3 x silver dollar types (w/red anal fins) 4" long
2 x geophagus 1 x 4" and 1 x 3"
1 x balloon molly 1"
1 x dalmation platy? "2
1 x sailfin platy? 2"
5 x black widow tetra 1"
1 x red platy 1" (was 3)
2 x small angels 2"

 

[Chasing Puck]

Fish will cannibilize from a dead fish, even if they had nothing to do with the death.

When did you last feed? While reduced feedings are beneficial, fish do need to be fed--every other day will help reduce the amount of waste produced without harming the fish in anyway.

However, it's highly unlikely that this killed the platties. More likely, the stress of the move, the changing water chemistry (what was the pH before? Were the fish acclimated to the new water?), and the presence of ammonia and nitrite contributed to the problem.