Help Please Fish Dying!

[saluki]

Hi guys i have a clearseal tank 3 and a half foot, in the last few days i have lost 3 clown loaches and 1 cardinal and 2 zebra danios, i have done a water change 25% on Monday and tested the nitrate level which is 0, i really dont understand whats going on, the clowns were just sitting at the bottom really breathing fast then just died, all the other fish look ok now swimming around happily but they do seem to be breathing very fast? im now scared im gonna lose all my fish, its a well established tank and they have been happy in there for about 1 year, i have a fluval 4 filter. any suggestions?

 

[always4lora]

You should check your water stat's nitrate at 0 is not normal you should test for ph, nitrIte and ammonia

 

[KittyKat]

pH, nitrite, ammonia (as requested above), temperature, filtration, full stock list, how long have you had what, decor, age of tank, did you add anything new to the tank recently?

Fast breathing is normally a sign of oxygen deprivation, but most fish would exhibit it if that was the case. It would help if you could provide details of all the above.

 

[grumpysteve]

as the fish aren't near the surface of the water, but breathing fast, it could be an internal or bacterial infection. don't suppose you've seen any of them poo recently? if it's a bit stringy looking then it would be an infection. generally if its something to do with oxygen levels the fish would be at the surface