-50% on a selection of fish food
Nitrifying bacteria convert the ammonia released by fish into nitrite, then into nitrate, the form plants absorb. A new filter has none: it takes several weeks for them to establish, a process called cycling. Starter bacteria speed up this stage, maintenance bacteria revive a filter after a treatment, a clean-out or the winter, and some strains break down the sludge at the bottom of the pond.
Monitor ammonium and nitrite during cycling with drop tests. The article The nitrogen cycle in aquaponics explains each stage.









