The best pond filters for koi ponds will help keep your pond clean and beautiful to look at.
Bead filters are generally smaller and employ a slightly different method of filtration. The chamber is packed with beads, which serve as the filter. As material is brought in to the filter, the beads trap the material and therefore filter the water. They also help in the process of nitrification. This is a necessary step for any pond with fish. As fish release excrement, ammonia will build up in the water. The process of nitrification cleans the ammonia by converting it to nitrogen.
If you have a small pond then a trickle filter may work. These are most commonly seen in indoor tanks, some people have had success using them in outdoor ponds. These type of filters are designed to pull the water out of the pond and drain it onto a filter screen. It is a good filter for the nitrification process, but can be a hassle to deal with in an outdoor pond setting.
This filter basically employs a standard filtration method and includes the release of beneficial bacteria in to the pond. These are probably the best filters for a koi pond. They require little maintenance and help to maintain the entire eco-system.