What does it mean when my ammonia is down to 0 but my nitrites and nitrates are up a little bit. Nitrites read .25 and nitrates were at .5. Does this mean that I am establishing a bit of bacteria, finally? I have a 10 gallon with 6 zebra danios and 3 cory catfish. I do a 25-30% water change daily. I hope I am finally establishing some bacteria in my tank. Even if it takes me several more weeks to get it fully cycled I will feel a bit better!!