1" drain really 1000gph?

Byrd · May 22, 2020

so I've always based my 1" drains off of 700gph but I've also heard they are capable of 1000gph. I'm honestly questioning that it may be more at this moment because I am currently running a jebao 18000L (5000gph roughly) in my setup plumbed with a return of 1.5 that splits to twin 3/4 in the DT. Its a 7ft return made out of smooth wall flex hose with 2 gradual 90s. I can run my pump at 100% with twin 1" drains and valves fully opened and they keep up without a problem. The drains have about 3" of water on top of them in with the vavles open. Now I don't run it like that normally because that creates a ton of noise from the large drop from the weir to the drains but with tuned in I run vavles at 3/4 and the pump at 75% so by duros work properly and i have a 1" drop from the weir.

Vette67 · May 23, 2020

According to this chart, 1000gph on a 1” drain is pretty close to what this says on a gravity fed line.

Byrd · May 24, 2020

Yeah I've seen the chart but where I am lost is, being conservative on head loss, I'm pushing 3500-4000gph and thats returning through two 1" lines. Thats 1750-2000gph in each 1" return

ca1ore · May 24, 2020

You sure you’re getting that much out of your Jebao? How are you measuring it? I’ve played around with 1” siphon drain quite a bit and the most I can get out of mine is 1,200 .... and that’s with 10 feet of negative head. At the moment, measured with flow sensors (so some error %) my PanWorld 250 is pushing 1,600 up .... 900 down the main 1” siphon drain and 700 split between two other 3/4” siphon drains.

K7BMG · May 24, 2020

Are you basing your pump GPH by the specifications that came with the pump, or are you using a flow meter?

If your using the chart I have found that no pump has ever come close.

I have a Varios 8 rated at 2700gph.
4.5 feet of head pressure two 90s and a 45 open ended.
I plumbed it with 1 inch and my flow meter showed 900 gph.
I re-plumbed with 1-1/4 and now get an average of 1260 gph.
Still far below the pump chart.
I have double checked as I have two Varios 8s, and two identical flow meters. Swapped them out to see if one was better or had an issue.
No matter the combination the results were within 10gph with the 1-1/4.

I have 2 one inch drains in my overflow on my tank, one is wide open, the second is probably 3/4 open.