Bead filters combine both biological and mechanical filtration in one compact body. Bead filters are one of the best choices for koi pond filtration. Especially if space is limited.
Bead filter media has a high biofilm surface area for bacterial growth so they are able to process the waste from heavy fish loads. The beneficial bacteria convert ammonia into harmless compounds producing excellent water quality.
Bead filters are easy to maintain and backwash, usually by simply by rotating a multi-port valve on the filter. The backwash cycle does the dirty work for you, by agitating the filter media and rinsing the trapped debris out of the filter