plumbing question on return

[PedroYoung]

I'm bringing 1.5" return line from my basement sump which I'm teeing off into 2 1" lines for the dual returns in my 200G. My question is if it matters (and how much) if the tee isn't under the center of the tank. It will be much easier if the tee is offset by about 1 foot (six foot tank). So basically 2' horizontal run on the right side, 4' on the left side before turning up vertical to the returns. I'd like the flow from each return to be close to the same.

Picture of lines above sump (2 x 1" returns on the outside and 3 x 1.5" lines from overflow in center).
image by Peter Young, on Flickr

Picture of tank with plumbing
image by Peter Young, on Flickr

Picture of sump with return pump plumbing dry fit
Untitled by Peter Young, on Flickr

So instead of coming of the sump and angling to the wall to hit center I'd like to go straight back to the wall and straight up to the tee. Sorry if I'm not being clear.

 

[WVNed]

The flow divides by back pressure. If the 2 pipes aren't identical the flow wont be the same. Add a valve to one. They aren't identical. The flow wont be the same.
It's a can of worms.

I would be tempted to put flex PVC of equal length between the ends you have to keep them identical.

Perhaps someone smarter than me will reply.

 

[ca1ore]

Back pressure on each diverted leg will determine flow; though I suspect just one foot of straight pipe as the variable won't make that much difference. Agree that putting a ball valve on the shorter of the two runs will allow you to balance them, though the valve will add a bit of additional back pressure. FWIW, I have started using cepex 1 1/4" ball valves on all my 1" plumbing runs. They're actually cheaper than the 1" valves (though about equal once you buy a couple of bushings) and restrict flow less.

Smart to elevate the sump. Less head pressure on the pump and you can light a chaeto refugium (if you plan one) from both above and below.

 

[Hemmdog]

I had the same issue on my recent build. Just added a hydroseal ball valve to the shorter piped side, I keep it 15% closed and it provides even flow for me on both sides.

 

[Eagle_Steve]

I would not worry about the small difference in flow if it was me. We use wave makers and such to get variable flow and more of a chaotic flow if possible, so I see it as one more thing to add to making the flow a little different from one side to the other.

 

[Mike.P]

The flow divides by back pressure. If the 2 pipes aren't identical the flow wont be the same. Add a valve to one. They aren't identical. The flow wont be the same.
It's a can of worms.

I would be tempted to put flex PVC of equal length between the ends you have to keep them identical.

Perhaps someone smarter than me will reply.

Back pressure on each diverted leg will determine flow; though I suspect just one foot of straight pipe as the variable won't make that much difference. Agree that putting a ball valve on the longer of the two runs will all ow you to balance them, though the valve will add a bit of additional back pressure. FWIW, I have started using spears 1 1/4" ball valves on all my 1" plumbing runs. They're actually cheaper than the 1" valves (though about equal once you buy a couple of bushings) and restrict flow less.

+1

I don't think offsetting them by that little will make a night and day difference in flow to each side, but it will affect it... Put a valve on the shorter side so that you can dial it back, in order to equalize the flow. I'd put a valve on both sides, it's cheap and easy, and finer control never hurts.

 

[dugthefish]

I would not worry about the small difference in flow if it was me. We use wave makers and such to get variable flow and more of a chaotic flow if possible, so I see it as one more thing to add to making the flow a little different from one side to the other.

This

 

[PedroYoung]

Thanks for all the replies. I will have ball valves in each leg in order to perform maintenance etc so if there is any appreciable difference I'll just dial back the short side. Thanks again to this great community!!