Confused about fishless cycle reading.

[Angief44]

My 29 gallon tank has been cycling 4 weeks now using bottled ammonia. Ammonia spiked, nitrites and nitrates spiked.

My nitrites finally went to zero yesterday. I figured I was cycled and planned to do a large water change to get the nitrates down tonight before I add fish. I dosed 5ppm ammonia last night and have found now (slightly over 12 hours later) my nitrites have jumped back up again.

Any ideas why the nitrites spiked after being at zero yesterday? Did I add too much ammonia? I haven't done anything to the tank that would have disturbed any bacteria since yesterday. I don't get it.

Any help us greatly appreciated. I really want to add fish tonight but obviously will halt my plans unless nitrite goes to zero. Thanks!!!
Edit: Should add that ammonia is at zero and being processed within 12 hours

 

[jlk]

Welcome to AA!!!

How much ammonia were you dosing prior to adding the 5ppm? It sounds like you may have added a bit more than needed and your bacteria were not able to able it. Not a big deal though! Don't add anymore and wait for ammonia and nitrite to zero out completely before adding @4ppm. If your tank can zero out 4ppm fully to nitrate within 24hrs (not 12hrs), then its safe to say your cycled. When you do the nitrite test, make sure it stays blue the entire time and does not turn from purple to blue. Please ask if you have questions!

 

[light_angel_7]

I've had a similar incident with my fishless cycle. After a few weeks of cycling my tank my readings were 0 ammonia 0 nitrites and 10 nitrates. After I added ammonia I tested the water a few hours later to find that my nitrites were up again and that ammonia was a 0 then the nitrites would completly vanish in 12-24 hours and reappear when ammonia was added again.

When you add the ammonia again tomorrow I would test it a few hours later, some time a night and again in the morning. If it shows up as 0 for nitrites and ammonia then your cycled and you can add some fish.