I decided this time around to try Fritz 900 for bacteria in my tank. I dumped it in around 2 weeks ago along with the recommended amount of ammonia drops. The testing now has me a bit worried. In the last 5 days my nitrite has not moved at all, but ammonia appears to be 0 and nitrates are present as well. My question is, should I add more ammonia drops, do a water change or just let it sit? I am assuming my cycle stalled somehow. Not sure how though. Thanks!