Fish dying???

Question

Okay, I've been running a 46gallon aquarium for more than 4 yrs, and clean it every month. I have a variety of fish that get along very well, but just recently, I had 4 die on me and 1 is beginning to act all speedy and hyped out as if he were stressed. This is the story: I had just cleaned out my tank, and I added a conditioner that I haven't used in yrs (I've used it before but never had a problem; it's called Tidy Tank) since I ran out of my normal conditioner. But after I cleaned my tank, I went out with Mom to the store for about 1hr and half. Well, we came back, 3 fish were dead (a rainbow shark, albino rainbow, and a bala shark). I've never had a problem with these fish before. They were always the hardy ones and the peaceful guys (I know some of yall might say they're 'semi-aggressive', but I've never had trouble with them). Anyway, about 30 minutes later, my minnow died too... Now, my last shark (a red-tailed shark) is acting odder than usual. Could it be the conditioner? Help

Answer 1

old age :) get a betta

Answer 2

did you check the water temp when you changed it? could you have shocked your fish? ( I'm assuming not because you've been doing this for years, but it never hurts to ask.)

Was the conditoner you used just sitting around for years? Or its a brand you hadn't bought for years? If it was just sitting around maybe it could have been contaminated?

Answer 3

In the intervening years since you last used the conditioner, it's likely that your water supply has changed from chlorine to chloramine as a treatment chemical. Chloramine requires about twice as much treatment strength to break the Chlorine bond. It's also possible that if the "Tidy Tank" had been lying around for several years it had lost "strength". Your Black Shark probably has badly burned gills. If it seems to be "gasping" the problem is chlorine burns.

Answer 4

Your fish could be dying of old age. Or there could be a disease in your tank. Add a few fish and check out all their symptons. I could be the old water conditioner, so buy a new one. There might of been space issues in your tank. A rule to remember is 1 inch of a fish per gallon. Instead of having a really big variety of fish, try putting 2 of a kind to keep each other company. I really hope this helps. Good luck!