Setting up refugium - can I run UV from the same pump?

[TJ23100]

Hi all,

First time post but been lurking a while.
Short backstory: I have a Red Sea 425XL that's been up and running approaching a year, been very patient in stocking fish and NO3 has really slowly creeped up but never gone up over 5. As stocking is reaching it's limit I'm seeing NO3 creeping up and want to start maintaining it.

I'm setting up a refugium for more reasons that nutrient control. At the same time I'm adding a UV steraliser. Plan is to pump from the return section of the sump into a UV, which outputs into a refugium (previously ATO tank in the Red Sea) and then drain back into the other side of the return chamber and nearest the return pump.
Is there any reason I couldn't have my pump feed the UV, then output to the fuge then drain back to the return chamber of the sump?
Initially I'll be running the fuge ~8 hours a day but will increase as required for nutrient export. Only negative I can see if that the UV won't be on a whole bunch, but otherwise seems a good use of 1 pump.

 

[Quietman]

UV effectiveness is dependent on the light strength and contact (exposure) time. Since the light strength is fixed (not accounting for aging) we control the exposure through flow control. There are two ends of the flow spectrum for organisms most of us are concerned with (algae and pathogens). Algae being smaller require less exposure (1/3 or less exposure) than pathogens which are typically larger. However, some algae (certain dinos and yes, classifying them as algae for UV use) can double every 20 min requiring 8x turnover tank volume per hour to manage breakout. While pathogens are controlled at much less flow rates (2-3x).

Based on the above and what you're actually wanting to do will determine placement. While your suggested arrangement will provide some UV protection it's probably not the most effective arrangement for maximum protection. I would recommend at a min to plumb it directly in return for maximum flow (assuming the size of UV you have supports exposure levels at your return flow rates).

Ideally, the UV is on dedicate loop directly to/from tank but that's not feasible for most. I currently have on return for example.

Some is better than none though. Particularly as I feel a 'maintenance UV' requires less turnover to prevent breakouts than to control/reduce existing breakouts. You can also always set up a temp hose and pump to/from tank with a separate pump if you ever see a disease/dino breakout that occurs during current setup configuration.

Hope this helps some, good luck!