UV Sterilizer

[Mike T IL]

I am running 1" PVC for my return lines. I go through a Pentair 40W UV Sterilizer which the manual instructs to use between 943 to 1574 gph to control bacteria and algae. I am only getting around 570 gph with my current setup. I understand the flow rate is impacted by height, fittings, valves, etc... With my current setup, would upgrading to 1 1/2" PVC get me to my target range of 943 gph or higher?

Here is my current setup:

 

[Quietman]

I think you'd need a bigger pump...although not too familiar with the COR head/flow characteristics.

But if you're thinking about going in enough to redo your pipes (or are planning still). I'd highly recommend a closed loop just for the UV with an variable speed pump that covers both low flow/high exposure and high flow/low exposure situations for multiple organism types.

 

[Mike T IL]

Thanks Quietman...
My Apex COR 20 is a variable DC pump with a max of 2,000 gph. I am weary that a bigger pump would help as I can run my pump at 100% and I still only get 570 gph flow which is what I get with running it at 70%. I am pretty sure the plumbing is the major cause but I don't want to tear out the old plumbing and redo it with 1 1/2" if that is not going to increase flow rate to what I need.

I thought about a closed loop setup but I don't have any more room in my sump for another pump.

 

[Sam816]

honestly i am not liking the way its plumbed. water is pushed from the pump, from 1st T it goes to both ends of the UV? water will meet in the middle of the UV pushing from opposite direction. It will be very difficult to measure and adjust flow through the UV. without proper flow UV is useless. have you considered maxspect turbine duo? it has 2 outlets u can put one on the UV then through a stop valve to tank and other through a stop valve to the tank.
pump outlet 1 -> gate valve->UV -> stop valve(uni direction flow valve) -> tank
pump outlet 2 ->gatevalve ->stop valve(uni direction flow valve) -> tank
u can put flow measuring valve in the loop with UV too if you want.
Just a suggestion.

 

[Quietman]

Understand. And yes there is less head loss with bigger pipe so you would have more flow...just not sure it's going to get you where you need it. And I'd hate for you swap out all that as well. Still....that pump is rated at 20 feet head. Read some and they do say 1 1/4" is recommended with some going with the 1 1/2". You should be able to talk to someone here running a COR-20.

Suggest new thread with something like "COR-20 insufficient flow for UV" or something to get the people you need to respond.

 

[Mike T IL]

honestly i am not liking the way its plumbed. water is pushed from the pump, from 1st T it goes to both ends of the UV? water will meet in the middle of the UV pushing from opposite direction. It will be very difficult to measure and adjust flow through the UV. without proper flow UV is useless. have you considered maxspect turbine duo? it has 2 outlets u can put one on the UV then through a stop valve to tank and other through a stop valve to the tank.
pump outlet 1 -> gate valve->UV -> stop valve(uni direction flow valve) -> tank
pump outlet 2 ->gatevalve ->stop valve(uni direction flow valve) -> tank
u can put flow measuring valve in the loop with UV too if you want.
Just a suggestion.

when running through the sterilizer, I turn off the ball valve between the 2 T's, So the water us directed from the pump to the bottom of the UV up to the TOP of the UV and then up to the tank. I did this per the recommendations in the Pentair manual. If I ever need to bypass the UV, I turn the 2 gate valves off going into and exiting the UV and turn on the the valve between the T's. I would also close the gate valve. Then the water goes from the pump to the first T, up to the second T and then to the tank.

 

[Sam816]

what are you using the UV for? algae control or ich/disease control?

 

[Mike T IL]

what are you using the UV for? algae control or ich/disease control?

Both, this UV is for bacteria and algae. I have a second UV for disease control that is managed by my second return pump which has no problems with meeting the flow rate of 157 gph for disease/parasites.

 

[Sam816]

Both, this UV is for bacteria and algae. I have a second UV for disease control that is managed by my second return pump which has no problems with meeting the flow rate of 157 gph for disease/parasites.

In that case i would put it on overflow(inflow to sump) to maximize the water volume going through. It will reduce load off your return pump and save you from complex plumbing setup. Any bactrial bloom/algae will come down the overflow line and get zapped by UV & skimmed out by your skimmer. on top of that a UV on return line will castrate all pods going to the tank. you want them to be able to reproduce and grow. Put a manifold instead for future expansion/reactors.

 

[DCR]

Yes, going with all 1-1/2" piping including the flow meter will likely get you to at least close to 943gph. According to the head curve, the COR-20 should put up about 13 ft of head at 570 gph, which means you have about 9 ft of friction head loss. The frictional head loss is proportional to the square of the velocity or the diameter to the fourth power. Just based on OD, it should drop the frictional loss to about 1.6 ft at 570 gph and 4.4 ft at 943 gph. Add the 4 ft of elevation and it will need to put up about 8.4 ft which is very close to the COR-20. May still be a little short, but those flow meters are very restrictive and going to a larger meter there will help a lot.