What does NO3 in the aquarium mean in practice?
Nitrates accumulate as a product of nitrification and are removed mainly by substitutions, plants and special denitrification processes.
When does it matter?
Constant growth indicates feeding and stocking balance, and the level required depends on the sensitivity of the organisms.
Which solutions are related to it?
Control with an appropriate test range, limit nitrogen sources and perform regular changes with prepared water.