weird cycle ....

[geowashlaw]

I've been cycling my old tank to give to my neighbor's kids for about 4 weeks now ... have had consistent readings on nitrite and ammonia every day now for about 10 - 12 days ... I add 2.5 ml of ammonia to get to 2 - 3 ppm and every day it is down to 0 ... nitrites about 3 - 4 ppm ... yesterday the nitrites went down to about 1 ppm ... thought it was almost through ... today ... nitrites at 0, but ammonia reading 4 ppm ... which is weird because the 2.5 ml only brings it up to 2 -3 ppm ... the readings seem like the cycle hasn't even started ... what is going on???

[geowashlaw]

I think I have this mystery figured out ... let me know if you think this is correct .... about 5 or 6 days after the nitrite showed up and about 4 or 5 days before they disappeared, I changed the filter and pulled out the old gravel from when I had the tank set up previously ... see, when I started the cycle, I used the filter that had been running with my fish in the tank and bagged up the gravel and put in there ... the filter was literally starting to fall apart by the time I changed it out ... I was thinking by then (5 or 6 days after the nitrites showed up) that there would be enough bacteria in the new gravel to keep the cycle going ... now I think I was wrong and that I just killed the cycle ... I rinsed the filter from my new tank in the tank today and am hoping that will restart the cycle ...