1/4" or 3/8" tubing for ro/di infeed ?

[connecticut cichlids]

I know 1/4" tubing is pretty much the standard for the input, but is anyone using 3/8" tubing to feed there ro/di unit?

[JohnnyBassMan]

No, 1/4" tubing here. Be nice to go bigger.

[1628mna]

im sure if you have the tools and skills you can drill out that hole and tap it to a bigger size but the way i look at it if its not broken dont fix it. there has to be a reason that the manufacture went with a 1/4 instead of a 3/8, im thinking maybe the seals wouldnt be able to hold the pressure of water . i have a 1/4 in. too. but if you do figure out a way to do it and succeed by all means share.lol good luck.

[cmm1970]

You will not need anything larger than the 1/4" tubing to run your RO unit. You do, however, need adequate line pressure for your RO membrane to operate at the rejection rate you expect based on the manufactor specs for the unit. So, do buy an inline pressure gauge and see if you have something close to 60PSI to run your unit on.

I have 47-55PSI so my unit is running under pressure. I am adding a booster pump and a second membrane to increase my production rate.

Since the units do not produce huge volumes of water, the increased diameter of tubing will not help the production rate on your unit. Increasing the line pressure with a booster pump will increase your production rate and help maintain the rejection rate you may be hoping for with your membrane.

[Reefer08]

Their is no point in having 3/8th inch. 1/4th inch is enough. Ive actually never seen anyone use 3/8th. If your water pressure is low then you'll need a booster pump. Currently my ro/di is having 85psi.

[Harry_Fish]

It would be an easy matter to go to Lowes and get the fittings
to go from a 1/4 inch John Guest type fitting to PVC then back
to a 3/8 inch John Guest type fitting.

I was just at Lowes 2 days ago, I plumed in a John Guest fitting
via a valve to my supply line, I did not see a 3/8 to 1/4 fitting.

If I was going to do a longer run I might consider going to 3/8
I'm not sure if surface friction would be a factor but I do recall something about keeping the tubeing under 25 feet.

[JohnnyBassMan]

I use 1/4" and also have about 85psi with no problems. Just takes time.

[connecticut cichlids]

Thanx for the advice guyz...:)