Good morning. have put off asking this for a lot of years. Our pond is 1500 gals., with a Savio skimmer and filter, waterfall. has a 3200 gpm pump and one 57 watt UV light, use to run 2 of these. The filter media I have use from day 1 is a narrow green ribbon in the filter and does a really good job. We have 4 large koi maybe 20" and 5 years old and 12 leftover from 70 or so that showed up one day, wasn't planned. We gave away about 60 and kept 12, they are 8 to 10". I feed the fish once a day around 4PM and they get 6 oz of Koi food. My problem is that I have to clean the filter out about every 5 days and it is full of muck for lack of a better work. I have this filter plumb away from the pond and open a valve to drain the filter only. I then start pulling out the ribbon a little and a time and rinse as I pull out, I do this until I have it all out and clean. I shut my valve off and put ribbon back into filter and add water to fill filter. Turn the pump back on and sit and enjoy. I have been doing this same procedure for 10 years. Would like to know if there is something I'm doing wrong, the water is clear. I will try and attach 2 pics of my pond. Thanks.