Return plumbing with UV

[vdubers]

I purchased a 80w deltec UV and hard plumbed it into my return line with 3/4 pipe.

However with my dc pump rated at 4000 lph was only getting around 900 lph vs around 2500lph before the uv was installed.

Ok I figure a larger pump is needed. Purchased a dc pump rated at 12000 lph thinking it would be overkill but I can turn it down but still only getting around 1400lph on max.

Is the size of my piping limiting me? I can go up a pipe size or two but the UV itself has small elbows on the in and out side so not sure increasing the pipe size itself will make much difference?

Both pumps are on max when I measured flow. Thanks.

 

[Coolcasino]

How are you measuring the lph? The pipe diameter is limiting you and if you cant increase the diameter of the in and out it might mean that UV isn't designed for more flow than that. Since you have an extra pump why not install the UV standalone with it?

 

[vdubers]

How are you measuring the lph? The pipe diameter is limiting you and if you cant increase the diameter of the in and out it might mean that UV isn't designed for more flow than that. Since you have an extra pump why not install the UV standalone with it?

Thanks for your reply. Sorry for my delay. I am measuring flow by timing how long it takes to fill up a container then using a calculator.

The UV is rated for 3000lph max. It’s a huge UV so no room under the sump and if it’s stood up next to the tank not sure running a separate pump will improve the flow all that much since there will actually be more piping if I return it to the sump.

So increasing the pipe size won’t make any difference if the UV elbows are small anyway?

 

[Buckeye Hydro]

What size are the UV ports?
What size are the elbows you screwed on to the ports?

3/4" pipe will flow around 11 gallons per minute (2500 lph) at around 50 psi pressure

 

[TheBear78]

If it's the UV I'm thinking of then the standard elbows do look restrictive. Do you have space to change to larger bore, larger radius elbows or even straight connectors with elbows in the pipework?
I don't have a UV currently but if space isn't a problem I would always prefer to keep my return pump and plumbing separate. The additional plumbing to get to and from the UV won't be helping the flow rate either.

 

[vdubers]

What size are the UV ports?
What size are the elbows you screwed on to the ports?

3/4" pipe will flow around 11 gallons per minute (2500 lph) at around 50 psi pressure

Thanks the uv ports are 3/4” (well they take a 3/4” connection) and the allows are 1/2” or 15mm.

If it's the UV I'm thinking of then the standard elbows do look restrictive. Do you have space to change to larger bore, larger radius elbows or even straight connectors with elbows in the pipework?
I don't have a UV currently but if space isn't a problem I would always prefer to keep my return pump and plumbing separate. The additional plumbing to get to and from the UV won't be helping the flow rate either.

I could theoretically have the UV horizontally over my sump but no space for it vertically under there and maintenance would be trickier.

I did try doing away with the small elbows this morning with 3/4” connectors but that didn’t make any difference at all. I’m not sure why they would supply it with such small ports and elbows if it’s rated for 3000lph for algae control.

 

[Buckeye Hydro]

Yes 1/2" elbows will limit flow. 1/2" pipe/fittings will flow about 5 gpm (~1200 lpm) at ~50 psi

 

[vdubers]

Yes 1/2" elbows will limit flow. 1/2" pipe/fittings will flow about 5 gpm (~1200 lpm) at ~50 psi

Thanks will try increasing the pipe size and the elbows on the UV to 3/4 straight connection.

 

[vdubers]

Just to update the thread thank you for your help I changed the pipes to 25mm internal diameter flexible tubing getting rid of all elbows and also got rid of the elbows that come with the UV and now I am getting the same flow on the minimum power level that I was previously getting on the max power level. So whether it was getting rid of the elbows that solved it or the larger tubing I’m not sure probably a combination of both. Thanks again for the help.