Placement of uv steralizer

[gregzz4]

I have mine running on it's own pump. It's after the socks and dumping back to the socks - just to filter out anything it kills
If I recall correctly, I'm running my 10 watt at about 225gph

Run your outlet into a bucket to determine your flow rate

Don't know if you need this info, but here you go;
For Algae control 40-50gph/watt is fine
For General Sterilization 20-25gph/watt
For Sterilization of many Bacteria and Viruses 10gph/watt

As Mindy said, check your manual. It should have a min/max flow rating