The PondKeeper filter utilizes a totally unique backwashing jetting system we call the "FLUFF-N-SPIN" system. Not only does the internal design of the filter allow for a "FLUFFING" of the media during backwash, but spins the bed and each individual piece of the PondKeeper media. This causes the media to get rid of any old bio floc that might be clinging to each piece, while holding on to the precious beneficial bacteria with in the filter. There is no other like it. Due to the "FLUFF-N-SPIN" agitation system and the design of the media, these units backwash beautifully using any low amperage koi pond pump.