Definition - What does Biological Filter mean?
A biological filter is a water filtration system that relies on natural elements like microorganisms and bacteria to serve as the primary filtration apparatus.
A biological filter can also be the completely natural plantings of cattails, sedges, or other marginal plants.
MaximumYield explains Biological Filter
A commercial biological filter often comes in the form of a box that contains a sponge or hair curler-like material where beneficial bacteria can grow and feed on the impurities of the water as it flows through the box.
A mechanical biological filter should not serve as the only form of filtration, however, and should be enhanced through the planting sedges or other water plants.
A mechanical biological filter can be bypassed altogether and also be built completely comprised of the plant material selected for a body of water.
In the marshy area of a pond, for example, cattails perform almost the same function as a human liver. Their tuberous roots attract and absorb impurities in the water.
Marginal plants such sedges or marsh marigolds are also excellent for creating conditions for beneficial bacteria that can help clean the body of water.