UV Pump Size/Placement

Veteran Reefer · Nov 5, 2021

I'm installing a new 40w Aqua Ultraviolet and wondering if this is overkill. I have a sicce SDC 7.0 on the way and have to choose which to use for mixing station and which for the sterilizer. I'm currently using another M2 as my return pump on my waterbox reef 220.6. Any suggestions or comments would be appreciated. Thanks!

Quietman · Nov 5, 2021

How big is tank? For full UV protection from algae and pathogens there are two different exposures. For algae you'll need to provide at least 8x tank volume per hour at min exposure 30,000 uw/cm2 to keep up with high reproduction rate of certain algae (dino). For pathogens (inch) the higher exposure is needed of min 90000 uw/cm2.

You can do both with constant flow if uv large enough and tank small enough. Otherwise variable speed and will need to adjust based on whats needed at the time.

Veteran Reefer · Nov 5, 2021

Quietman said:
How big is tank? For full UV protection from algae and pathogens there are two different exposures. For algae you'll need to provide at least 8x tank volume per hour at min exposure 30,000 uw/cm2 to keep up with high reproduction rate of certain algae (dino). For pathogens (inch) the higher exposure is needed of min 90000 uw/cm2.

You can do both with constant flow if uv large enough and tank small enough. Otherwise variable speed and will need to adjust based on whats needed at the time.

Waterbox reef 220.6 @Reefing Mama and I decided to go with a DC pump to allow for usage in both applications as needed. Although I am not sure if the flow rate is shown in the sicce app for the SDC 7.0, I know it can be monitored in mobius for the M2

Quietman · Nov 5, 2021

That's a beautiful tank...congrats. DC pumps make that a great solution. I don't think the SDC 7.0 is actually quite big enough. You need 1760 gph to get the 8x turnover recommended and with head loss I think it could end up being much less than the stated 1900 gph (isn't it always). I don't know you're flow arrangement but even a closed loop to/from tank going through the few 90 degree bends for the UV is going to knock it down below that. I may try both and do a bucket and stop watch measurement to see which pump deals with head loss best.

Quietman · Nov 5, 2021

Forgot to add...I'm not sure it's worth upgrading pump if your at 6x or 7x. To get rid of my dinos during a breakout I had to have 8x flow but to manage them it's lower. I have a Tunze DC pump that maxes at 580 gph (with head loss measured by bucket it was just about 350 gph) and it's only on about about 1/2 speed so figure it's pushing maybe 200 gph. For my 43 gallon RSR170 that's fine to keep dinos away. But if I drop it anymore (which I did once) then hello dinos.

Veteran Reefer · Nov 5, 2021

As far as pump placement, I was thinking of drawing from the area where the drain drops into the filter sock area and placing output line in return pump chamber.