Pond is approx 5000 gal, goldfish only. Have 2 smaller Filters with uv, and then my main pump goes to a 55 gal drum, 1/2 the water goes to waterfall, rest to a 40 gal drum, then to waterfall. Have not had a problem, but age is making it harder to clean filters. Need a good filter material that would be easier to use, hopefully in some sort of pads. What is a good recommendation. Pond this winter froze and thawed 5 separate times (live in Central NY), and luckily lost no fish. Thanks