Okay i have a 5000 gallon pond with a double waterfall koi, goldfish. The waterfall pump sits in a pondsweep skimmer box. With a leafbasket, 2 pads and water gets shot up the hill with a ebara dominator pump rated at 10000 gph, to a savio filtet falls box with another filter pad down the stream to another drop off into the pond. We also have a pressurized tetra filter at 4000gph which is not true. The pump sits in a diy prefilter ( trashcan) with hole in the bottom. So since the pond was built we have been through 2 pressurized store bought filters. The sun just tears them up. The current one is leaking out the top and sides. It was dug down in the ground. Right now i just stuck it in the pond so the pond doeant leak out. So my question is how can i build one large enough for the size. And since the whole pond is rocks, i dont want it to be a eyesoar either. I can post pics if that helps.