Right!dixaisy930 said:Well, I think you probably have two problems with the tank...
The first is you do have too many fish in the tank. A good rule of thumb is one inch of fish to one gallon of water. You need to use the fishes final length for this (for example, guppys and platys usually get to between 2 and three inches, so one would need about two gallons of water).
The other problem is a common one...your tank has not cycled. There are alot of good posts and articles about this, but basically is means you need to let your tank run for about 3 to 5 weeks so it goes through it's natural ammonia and nitrite/nitrate spykes that can kill some fish.
Hope this helps. I'm sure it'll all work out.
Yup! That is a common diagnose for most first timers. I had also these kinds of
problems when I first started my aquarium hobby.
I think aside from the regular filter,you should also add some natural plants, in order to add more oxygen .