Our levels lately have been Ammonia .25 Nitrite 0 Nitrate 5 Today they were Ammonia .25 Nitrite .25 Nitrate 5 What could be causing nitrite to go up again?? Took out our old plants that had diatoms on them and replaced them with new ones. We soaked them in treated water.. did a water change yesterday after a week of not doing one 30% with prime and stability. (A little cleaning) in one spot of the tank. Anyone know what would cause this?