Every koi pond and water garden must have some form of filtration on it. Above we have filters that will fit every budget and pond. We grouped the different filters into basic categories that reflect their design style. Because of the wide range of price points within any specific category, please try not to compare a $100 filter to a $3000 filter as they will have very little in common.
Filters will serve many purposes. The main two functions of a filter is mechanical filtration, the removal of solid waste, and biological filtration, which will convert the ammonia produced by the koi into nitrates. When choosing a filter system you must consider both requirements. Some filters have combined mechanical and biological filtration into a single easy to operate filter, others are dedicated to completing only one stage of the filtration system.
The thing to keep in mind with your filter is that it is only one part of the over all system. The entire koi pond must be taken into consideration when choosing a filter. Size of the koi pond, stocking density, pump flow rate and how water will leave and return to the pond are just a few considerations when choosing a filter for your koi pond. For more information please read the section on koi pond filtration.