rdwc return line

doniboy

Well-Known Member
I'm doing a DIY reverse pressure under current RDWC system with 2" pipes. My question is what size pipe should I use for the return pipe and why? I'm asking because I seem a smaller return line in most other setups I've seen.
 

vostok

Well-Known Member
big as you can find..18 inch diameter is good ....lol

its the return that will ALWAYS block

with roots, and trash thrown in by the public ....lol

good luck
 

loftygoals

Well-Known Member
smaller return like 1/2 or 3/4 - as you don't want to outrun your recirc flow....
This is a common misconception (and I understand why).

If the return line was purely gravity fed then pipe diameter would make a difference. But as you'll be using a pump to control this flow it is independent of pipe diameter (unless you're restricting things with a tiny, tiny pipe).

To understand this better ask yourself: which scenario provides more flow, pumping 1 GPM in a 1″ pipe or 1 GPM in a 2” pipe? Well 1 GPM is still 1 GPM regardless of the pipe size!

So really you want as big as a pipe as possible (to stop root blockage) with a correctly sized pump (which controls flow).
 

widowmaker31

Well-Known Member
This is a common misconception (and I understand why).

If the return line was purely gravity fed then pipe diameter would make a difference. But as you'll be using a pump to control this flow it is independent of pipe diameter (unless you're restricting things with a tiny, tiny pipe).

To understand this better ask yourself: which scenario provides more flow, pumping 1 GPM in a 1″ pipe or 1 GPM in a 2” pipe? Well 1 GPM is still 1 GPM regardless of the pipe size!

So really you want as big as a pipe as possible (to stop root blockage) with a correctly sized pump (which controls flow).
Not with my UC System - I run a custom setup so it's VERY crucial and I'm an engineer so I get GPM, etc, thank you for the lay intention, best of luck!
 

jijiandfarmgang

Well-Known Member
make the min size the inlet of pump. If you want restriction use a smaller pump or a ball valve.

But I think undercurrent is dumb. Why mimic something sub-par?

- Jiji
 

doniboy

Well-Known Member
make the min size the inlet of pump. If you want restriction use a smaller pump or a ball valve.

But I think undercurrent is dumb. Why mimic something sub-par?

- Jiji
Undercurrent seems to be a popular method used by many with much success. What, in your opinion, makes it "stupid" and "sub-par?"
 

jijiandfarmgang

Well-Known Member
Undercurrent seems to be a popular method used by many with much success. What, in your opinion, makes it "stupid" and "sub-par?"
I didn't say stupid, I just said sub-par.

I say the same thing about stinkbuds aero setup.

People don't like it when I say that but just trying to help.

- Jiji

Edit- because well basically its sub-par lol. The best growing site in the whole undercurrent setup is the epicenter. Except you don't actually grow in that location lol. And to try to makeup for that fact you have to run an airpump(s) and airstones.
 

doniboy

Well-Known Member
I didn't say stupid, I just said sub-par.

I say the same thing about stinkbuds aero setup.

People don't like it when I say that but just trying to help.

- Jiji

Edit- because well basically its sub-par lol. The best growing site in the whole undercurrent setup is the epicenter. Except you don't actually grow in that location lol. And to try to makeup for that fact you have to run an airpump(s) and airstones.
I miss quoted you. You said dumb which isn't much different I guess...

As far as being sub par, everything I've seen and heard thus far contradicts you, but I'll humor you. What is the superior growing method in your opinion?
 

jijiandfarmgang

Well-Known Member
I miss quoted you. You said dumb which isn't much different I guess...

As far as being sub par, everything I've seen and heard thus far contradicts you, but I'll humor you. What is the superior growing method in your opinion?
Most peoples grows are sub par lol.

Check the thread in my sig.

- Jiji
 

ttystikk

Well-Known Member
This is a common misconception (and I understand why).

If the return line was purely gravity fed then pipe diameter would make a difference. But as you'll be using a pump to control this flow it is independent of pipe diameter (unless you're restricting things with a tiny, tiny pipe).

To understand this better ask yourself: which scenario provides more flow, pumping 1 GPM in a 1″ pipe or 1 GPM in a 2” pipe? Well 1 GPM is still 1 GPM regardless of the pipe size!

So really you want as big as a pipe as possible (to stop root blockage) with a correctly sized pump (which controls flow).
You have an engineering background, don't you?

Well put!
 

ttystikk

Well-Known Member
I didn't say stupid, I just said sub-par.

I say the same thing about stinkbuds aero setup.

People don't like it when I say that but just trying to help.

- Jiji

Edit- because well basically its sub-par lol. The best growing site in the whole undercurrent setup is the epicenter. Except you don't actually grow in that location lol. And to try to makeup for that fact you have to run an airpump(s) and airstones.
BWAHAHAHA! I've been saying exactly the same thing about that under crapper for years now!
 

Airwalker16

Well-Known Member
make the min size the inlet of pump. If you want restriction use a smaller pump or a ball valve.

But I think undercurrent is dumb. Why mimic something sub-par?

- Jiji
I agree. I use submersible with a chiller. Pump in the res to supply waterfalls to buckets. Gravity returns the water to the res.
 
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