So your getting an 8x turnover in your dt from your sump.
Having the uv in your sump and returning that water into your dt 8x will still be good. Your going to be equal with uv sterilization to your dt and sump. Remember I'm using 55 watt on 3000 gallons in 100 percent sun. And it's more than efficient.
Try and you'll see.
Sent from my SAMSUNG-SGH-I997R using Tapatalk 2