frederick thompson
Member
I use mine after the filters mate. My water is gin clean. My system on both lines go from bottom drain 4 inch line. to rotary drum to nexus to dry pump to uv back to pond. My other line is skimmer. To ultra sieve 4 inch line to dry pump to uv to mid water return jets. Reason for uv after filters is no big stuff ends up in uv s. My set up works. I also have upper pond with plants. This acts also as filter. Good system for fish. All the best fred everyone has different opinions. On where to put uv. Like in pond pumps. And outside dry pumps. Is two reasons to differ. Best fred