Hi everyone! I have a 12ftX 21ft figure eight shaped pond about three and a half feet deep. I have an older fishmate gravity UV biofilter with 30watt uv, a hy-drive 4800 pump in a skimmer feeding both the filter and a waterfall at the other end of the pond. My Uv quit on my last summer and my water turned green, so I'm thinking of upgrading my filter system. I'm open to all ideas on upgrades. A couple of things I'm interested in is adding a bottom drain, and maybe hiding the filter system under my back deck Thanks!