From the horses mouth..

[fishhead]

Ok, after much conflict and discourse, I received a call from Aqua UV yesterday, the makers of my 25 WATT Classic unit w/wiper. The word is to go ahead and run it as my main return after the sump. At 500 GPH the unit has exposure rates of about 75,000uw/cm2, and ALL my water is being treated before returning to the display tank at the rate of ~5 turnovers per hour (500GPH).
For extra current in the display tank, I have a SCWD powered by a 780 GPH pump directly. So that is about 12 tank volumes per hour within tank with 5 of those leaving to the sump/fuge, PO4 reactor, denitrification reactor, big ol skimmer, carbon reactor and then back through the UV to the tank. Acceptable?

[burning2nd]

i dont have a UV

I dont think you need it,
Just IMO
If i could get one for free, i would totaly hook that unit up but other wise,

you have some good strile water?

[AQTCJAK]

I actually run a 57 Watt Aqua UV on my reef @ the shop 40 Gallons & pump only about 80-90 Gph through it it works perfect that way.

On my large tanks I run 200-1000 Watts @ about 500gph

[fishhead]

Originally Posted by AQTCJAK

I actually run a 57 Watt Aqua UV on my reef @ the shop 40 Gallons & pump only about 80-90 Gph through it it works perfect that way.

On my large tanks I run 200-1000 Watts @ about 500gph

I'm sorry, was that a 57 WATT UV on a 40 gallon tank? 90 GPH would be a little less than 3 turnovers an hour. Is that your main return after filtration?

Now, these large tanks you speak of, are they around 100-300 gallons?
A bit unclear still in my mind.