I'm about 3 weeks into a fishless cycle and was wondering if it's possible to have missed the nitrite spike in my testing. My ammonia usually takes about 48 hours to go from 4.0 to 1.0, then I repeat. My nitrites have been at zero for about 10 days and my nitrates are slowly climbing from about 5 to now between 10-15. I'm curious what I should do next possibly a large water change? Thanks !