Odd fish death

[fishoholic]

Originally Posted by Brent F

I have heard of this soon after a water change. One guy I knew when I lived in Edmonton had a tank maintenance service and had something similar happen after doing water changes in a couple tanks. He was using tap water with chlorine remover. The chemicals in used in the tap water were different one week and he had fish die in a number of tanks. The water tested fine.

This wouldn't be the problem if you are using RO water.

We use RO water, and the last WC we did before the fish died was last Sat. We did another WC last night after we found the dead fish and after we tested the water. It just so odd that the fish looked very healthy but were floating upside down and were dead.