OK, so reading through everything. I have had a UV filter and it didn't seem to do anything. I used it for several months. I have tried everything everyone has mentioned, the barley, more plants, big filter, new filter, big pump, little pump, etc., etc. Change the filter pads daily, don't change them. Nothing has cleared the pond. It took me 8-10 hours on a Saturday (I work full time) to build the skippy filter, I just don't know if I have energy left to now hook up my old filter and rig it with all the batting, etc., only to see no results. Sorry to be so skeptical but 7 years and thousands of dollars later, I can't see the fish. I've covered 3/4 of the pond with plants, used a shade cloth, culled the fish population.
So, why is it that some people seem to figure out the balance and others (ME) cannot do it? Would it have something to do with the climate? Denver has 300 days of intense sun per year and my pond has no shade and we're closer to the sun at 5280 feet above sea level. Or maybe I need to admit I have a black thumb for ponding?