Mechanical filtration physically strains solid debris, leaves, uneaten food, fish waste, out of the water using foam, pads, or brushes.
vs. Biological Filtration
This is different from what a biofilter does. Mechanical filtration removes visible particles; biological filtration breaks down dissolved, invisible waste like ammonia. A pond usually needs both, and mechanical media needs to be rinsed regularly or it becomes a waste trap itself.
