I did a fish less water cycle and after it was finished I got to looking at my filter and it had tiny black worms on it. So I changed it and a day or to after I brought some fish home and then a week after that my wife brought 8 fish home... So I'm pretty much doing a new cycle now... I do 30-50 pwc daily and my parameters are PH 8.2. Ammo .25ppm. Nitrite 0ppm. Nitrate 0ppm.