fish dying suddenly in new aquarium. Need help.

[Dunc@an]

I have recently started a new tropical aquarium. I got my tank and had it running for a week and made sure it was at optimum conditions before adding fish. The fish were looking healthy with no problems for a day until they started to die in about 10 minute intervals. Water and tank conditions are good and do not understand why the fish are dying. Any ideas?

 

[Crispii]

If you just set up the tank for a week, then I would assume that the cycle has not yet complete. The nitrogen cycle will usually complete at around 4-6 weeks. By any chance, do you know the parameters of the water?

 

[Essjay]

I agree. Can you tells us what the water conditions (ammonia and nitrite in particular) and the water parameters (pH and hardness in particular) are please.

Could you tell us how big the tank is and what the fish were?
Did you use a water conditioner (dechlorinator) when you set the tank up?
Have you added any other chemicals to the tank?


Even in an uncycled tank, ammonia should not build up enough to kill fish in just 1 day unless there were an awful lot of fish in a very small tank.

 

[Colin_T]

It sounds like something is poisoning them.
Do a 75% water change and gravel clean the substrate every day for a week.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.

Make sure you don't have any oil, soaps, grease, cream, hand cleaner, disinfectant, etc on your hands when feeding the fish or working in the tank.

Make sure you use a clean bucket for the fish tank. Don't use a bucket that has been used for cleaning anything else.

Post pictures of the fish so we can check them for disease.