Start over and give all your info so everyone can see what might be the problem.
What size tank
how old?
filters
live stock
etc.
How often you do water changes
What and how often you feed livestock
I would first off go get your own test kits and test your water. You can also take some in to your lfs and they will test it for you, but best to have your own.
I'm thinking you may need some more filtration also.
make sure you get your numbers and come back and post them.
SG
Amm.
Nitrite
Nitrates
If you can get live fish store to test for
Phosphates
good luck and post back soon with numbers and info.