This filter is amazing! We had gone all winter without filtering our Koi pond. With drastic changes in temperature, it became green and murky. After installing and running the filter for just over 24 hours, it was unbelievably clean. And cleaning the filter is easy. No need to take it apart and remove the sponge filters, just turn a switch to reroute the flow, like backwashing a swimming pool. Then turn a crank type handle to agitate the filter balls inside the filter housing. A clear spout lets you know when the water is clear. It's much better and a lot less money than more expensive filters!