Mechanical Filtering

• Building a filter for a koi pond requires mechanical filtration. Mechanical filtration removes debris from the koi pond. Deposits from fish and other debris settle to the floor of the koi pond, creating a habitat for unhealthy organisms to grow in the water. Mechanical filtration resolves this problem. A water pump is inserted into the pond, allowing the water to move the wastes to a catcher or settlement chamber.
  
  

Biological Aspects of a Koi Pond Filter

• Bio-filtration filters out unwanted bacteria and harmful organisms from the koi pond. It also transforms ammonia to nitrites; and nitrites are transformed into nitrates. Oxygen is cleaned. Good bacteria is introduced into the pond water through a bio-filter. The surface area of the bio-filter allows for more nitrites (bad) to cling on to the filter's surface. With a greater amount of surface area, the filter can produce more biological filtering. Many of the city aquariums use sand for bio-filtration. Water moves in through the filter top, and is mixed with the sand. The sand processes the bacteria from the water. Water moves up through the pump and is reintroduced into the pond. Sand filters cannot be made by non-professionals because water pressure is very high. The water pressure through the sand filter must be accurate and consistent.
  
  

Water Flow Components

• Koi pond filters can be built to slow water currents by introducing filtration components to the pond. Quite often a settlement chamber for mechanical filtration is placed in the base of the koi pond. Gravitational force naturally brings waste into the settlement chamber. Baffle plates are inserted into the water to act as a cushion against the water current. This allows the debris and waste to fall to the settlement chamber, where the debris and waste is collected. Media is a necessary component for koi pond filtering. Media will either be sunk to the bottom of the pond or float at the surface. Either method works. On the media is where bacteria grows, creating the necessary food for the fish. The media can be a layer of sand or beads, on which bacteria will mature over a period of weeks or months. Purchasing bacteria (cultures) at the store can mature the bacteria more rapidly than waiting for it to grow naturally. Tap water is never used, because it will kill the bacteria.