I"m new at this and I"m having trouble with ammonia. Fortunately the fish I have now are not dying or sick. I have done water changes and replaced the filter cartridge twice. My 10 gallon tank ran fishless for 2 weeks before I added fish and I lost 2 within a few days. I waited a week and get my water tested and the levels was border line between Non stress and stress so the pet store said they thought it was OK to get new fish. I got 2 more which now my tank consists of 3 total fish. I did get a test kit of my own and after a few days I tested the water and the ammonia was extremely high. I went bak to the fish store and they suggested to keep my current fish from dying a product called Ammo-Lock. Well my fish are doing fine but I still can't get rid of the ammonia after doing water changes and I am not detecting any nitrites. I just need some advice. Any will be greatly appreciated.