I've been spending a lot of time reading up on the water cycle for aquariums, but I'm still not where I need to be. And I've lost all but a couple fish. So here is what I have... 10 gallon tank is about 6 weeks old. I waited about 10 days before we put in fish. Also added one live Moss Fern. Now I realize the bacteria wasn't there. I had 2 mollies, 3 tetras and 1 catfish (all that is left is 1 tetra and the catfish). I tested at least once a week and continually saw 6.5 ph, 8.0 ammonia and zero nitrite/nitrate. Hardness is always around 150ppm. So obviously I needed some beneficial bacteria. I made a homemade K1 filter that I learned from DIY Joey. Just a filter with a sponge at the mouth and K1 inside a water bottle with air being pumped in. This took time but seemed to work. My ammonia is now at 0 ppm but my nitrite is sky high at 5.0 ppm. I just did a 25% water changed and immediately did another test. Still 5.0 ppm. So, the water didn't dilute it out. I have Prime conditioner and I'm going to try it. What else can I do to get the bacteria I need to convert nitrite to nitrate? It's getting hard telling the kids that the fish went to heaven! I see that missa124816 is having a similar issue, but the tests are different so I started my own thread.