Originally Posted by zingo
This is a 30 gallon tank which ahs been runnig for several years. I've had a few fish die lately (my favorite angel fish), so all i have is 6 cherry barbs and a cory. The pH is 7.0, and every thing else tests well. I'm sure that the problems i'm having with my tank is the lack of bio-film on my filter.
I'm sorry for your loss.
Is your tank naturally pH 7? Or do you chemically alter it?
Do you know the exact reading is the ammonia, nitrite and nitrate?
Have you changed, or washed in tap water, your filter media?
The bacteria in your filter will grow to handle the amount of fish you have in your tank but if it has been wiped out it will take time to recolonize the filter.
Do you use a dechlorinator/conditioner!
The more info you can give the more it will help us find out what's wrong.