Nitrite won't go down


Currently doing a fishless cycle (about 4 weeks in) and my ammonia goes from 2ppm to 0 in 24 hours. My nitrites however have been off the charts for about 2 weeks. I did a large water change to bring the levels down and dosed ammonia again but nitrites were back to over 5ppm the next day. Should I keep doing water changes or just ride it out? And should I keep adding ammonia?

temp is 80 ph is 7.4


it sounds like you have plenty of the bacteria that convert ammonia to nitrite, but now need to develop the bacteria t;hat convert nitrite to nitrate. That could take another couple of weeks, maybe more.

As long as the ammonia drops to zero overnight, keep dosing 2 ppm ammonia until you start to see the nitrites come down and the nitrates go up. However, make sure you do not dose more than 2 ppm ammonia. Once you get to 2ppm, it becomes somewhat difficult to read the ammonia color chart. Since your nitrites went up to 5 ppm, I suspect you may be dosing more ammonia than you think you are adding.

Latest threads

Top Bottom