running two UV sterilizers: both on the return pump, or one on return and one on closed-loop?

[Try'nNotToKillStuff]

I am re-doing my mixed reef 120g and I'm planning to run two Pentair 40 watt UV sterilizers. One I'd like to run at the Pentair recommended flow rate of 943 gph to sterilize for algae and bacteria and one running at 157 for protozoa bacteria. My question is whether I should run both off my return pump, or if I should put the 943 gph one off a closed loop (a la Ryan's BRS 360) and the 157 off the return pump? Doing the math, the two UV sterilizers would need a combined 1100 gph. I am currently running a large sump volume (currently about 80 gallons) and plan to continue that in the new tank. So, total water volume (minus the rocks and sand) I would estimate at 180 gallons. I'll do a more precise measurement when I set up the new tank. In any event, if I run both sterilizers off the return, then I'll need 6 to 7 times turn-over through the sump to power both UV sterilizers. Too much flow through the sump? Does your answer change if I tell you that I plan to run a rollermat?

 

[JumboShrimp]

I just like the concept of one off the return, one as a closed loop— so if you can swing it, go for it! And if you set up the loop for high flow (algae control), if you get a handle on the water clarity and feel you don’t need to run it all the time, it’s easy enough to shut off because it’s a standalone. Best wishes!

 

[1ocean]

Glad to read your posts, as I am thinking of a idea close to yours with 2 UV's.
I am currently doing a new 300 build 8ft longx30'wide x24' high to replace my 140. I designed and I am in the process of building 2 sumps,(tied together by 3" pvc pipe to balance out water when system is in feedmode or to keep water levels balanced while running) race track design 24"x24"x16"high. One bio and the other chemical both with mechanical pre filters. So having 2 UV's is my idea just as "jumboshrimp" mentioned the flexibility to turn the algae one off and on as needed.
So one UV dedicated to one sump. Also I like the idea if I need a replacement part or have to replace one it is cheaper then buying a bigger one.
What i been seeing is that the price for 2 is close or a few bucks more for two.
Just my idea but I am glad I see others are thinking like me...
Have a super great day...