Bog Filter , Enhanched Koi Pond Filtration

BOG FILTER -- Pond filter maintain water quality and make beautiful  koi  fish. Bog filter system employs a lush planting of gorgeous, water-loving plants to remove excess nutrients and improve water quality. A bog filter is an area dedicated for the dense planting of water-loving marginal or bog plants. It is a smaller, supplementary pond usually 10-20% of the size of the main water feature.

What Is Bog Filter

In essence, a bog filter is a natural wastewater management system for your koi pond. This effective example of biological filtration relies on plants to extract such pond pollutants as organic waste,ammonia, nitrite, nitrate, and phosphate before they can accumulate and negatively affect water quality. This natural filtration restores balance to the pond environment by increasing the ability to process or export excess nutrients. The result is cleaner,clearer, and healthier pond water.


What makes bog filters different from conventional pond planting is the manner in which the plants are grown. In bog filters, plants are grown hydroponically in relatively coarse, nutrient-poor substrate (pea gravel). This planting method "trains" the plants to search for nutrients in water rather than in substrate or planting media. Conventional potted pond plants passively remove nutrients from fertilized planting media and rely minimally on pond water for nutrients.


Furthermore, bog filters incorporate a circulation pump. This pump actively draws water from the main pond and introduces it directly to the plant root system. A diffusion system, similar in principle to a water fountain, is placed at the bottom of the bog filter. This water conduit system relies on the up-flow principle so water drawn from the main pond percolates up through the planting media and bathes the plant root with nutrient-rich water. This method not only increases water circulation through the root system for healthy plant growth but also provides additional mechanical filtration.

Bog Filter Construction

The "construction" of the bog filter now consists of creating a "mini pond" to house the water diffusing system and the plants. Start by designating a level area for the bog filter and construct a retaining wall out of landscaping rocks (this step is done right after liner installation). The area within the wall will become your bog filter. Installing an internal bog filter is most conveniently done during new construction. However, it can also be installed by temporarily draining the pond during spring.

For an external bog filter, locate it adjacent and slightly higher than the main pond. An external bog filter is similar in principle and construction to a waterfall and relies on a gravity return system. An external bog filter can be made using a liner or even a preformed pond.



Source:
Drs. Foster & Smith Educational Staff, Enhance Pond Filtration with a Bog Filter