I was about to go to bed last night (and actually get enough sleep) but I started feeling paranoid and decided to test my aquarium water. Well, there's nitrite. I have a very old (several years) API test kit. According to that, the nitrite was at about 0.5. According to my new tetra test kit, nitrite is at about 1.0. (It's kind of hard to read, colors don't contrast much). The ammonia test ran out of drops halfway through, so I don't know what that was at. I'm guessing the ammonia to nitrite part is still in place, but the nitrite is not being converted to nitrate! I don't know if the nitrite to nitrate bacteria could have somehow died after I added the fish. I did a 50% water change last night. I just wanted to know what steps I should take to let this part of the cycle reestablish without harming my fish. The tank is a five gallon with a single male betta.