mark shirah
Aquarium Advice Apprentice
i am doing a fishless cycle. nitrite showed up in about 10 days. kept up ammonia level at 2-3 all the time. nitrite spiked at day 30. one week later later nitrite went to 0 but i still have ammonia between 1-2. nitrate level is at 20. i have not added ammonia in 5 days. why do i still have ammonia after nitrite went to 0?