Originally Posted by Chris_Produces
Sounds like a mini cycle. As others have pointed out, your nitrites need to be down to 0 and your nitrates are crazy high. How often do you clean your filter and why did you toss the old pads? When you rinse the foam pad are you doing it with tank water or tap?
I clean my filter about every 3 months. I have always tossed the old pads, figured I have enough bacteria in the dirt and the 2" foam pad. I rinsed the foam pad with tap water. When I set this tank up it never "cycled" because of the dirt, I put about 30 fish in within a week and never lost one. This is the first time I have lost a fish in this tank, besides when they jump out.