Thanks for the reply
. In answer to your questions:
My water conditioner takes care of chlorine, chloramine, and heavy metals. It doesn't do ammonia, which is ok for me because I have no ammonia in my tap water.
I don't add anything else to the water. The weird thing is that I have 2 other tanks and all the fish in those are perfectly fine. Also, the deaths occur randomly, not following a certain time such as water changes.
I feed them a diet of flake food and frozen blood worms (thawed of course). The other fish also get these bloodworms, so I don't think that they are diseased.
When I clean my tank I vaccuum the gravel, but not all spots, and add aged water (it is room temperature but I don't change enough for it to make a difference in the temperature of the tank). I clean the filter pad when it looks dirty and clogged up. Usually once per month. I don't have any algae, so the tank never needs scrubbing.
I don't use any airborne chemicals or sprays in my room.
This just seems really wierd because these fish were living in toxic levels of nitrate for years. My parents never cleaned the tank, and the fish did not recieve a good diet. Then I take them and they all perk up, but start slowly dying quite a bit after the move. I did everything really slowly, and since the deaths came after the move, I'm thinking that it is unrelated. Also, I do things the same in all my tanks and all my other fish are fine.
Like I said, there is no more breeding going on, so maybe that was the only thing keeping the numbers up before? I really don't know.