A well-tuned filter system is essential for a clear and clean pond.

Dirt bring the pond is out of balance. Grasses, pollen and dust drifting on the one on the surface, fish waste, uneaten food, and also leaves fall from the pond bottom. This leads to opacification of the water sludge of ground and usually also a difficult to control algae growth. Decomposition processes (decay Ocidation UDN) consume oxygen and put excessive nitrite and nitrate free. The balance of the pond begins to tilt.