I am in the middle of fishless cycling my 55G, and not sure what exactly is happening. It has been going now for about 6 weeks, and up until recently was going exactly as expected.
I had been adding ammonia up to 5.0ppm, my nitrite started building and then spiked for about a week, it then started to drop, and nitrates started appearing. For about a week now my nitrites have been back at 0, and my nitrates are slowly increasing (last checked they were a little darker than the 20 mark on the API test kit). But my ammonia has not yet gotten to 0 once, it has got down to about 0.25 - 0.5 and I dosed it back up to around 2.0ppm, but its not yet gotten to 0 (and if anything now appears to drop slower than it did). If my nitrite has dissapeared what happens now? am I essentially back at square 1? will my nitrates die off because there is no nitrite for them to feed on?
Its getting a little frustrating as things were going as expected, and I am now not sure how much longer I have to wait before being able to add any fish to the tank. What is happening? and where do I go from here?
Edit: My water is soft and acidic (at least as low as the API kit will go) it has a sand substrate, some driftwood, fake plants and I am using Prime water conditioner, not done any water changes while cycling only topped up with conditioned water as required. Water temp is currently 82F while cycling. 2 HOB filters.