Booster Pump

brclark82 · Oct 31, 2023

I have low pressure getting to my RO membrane, in the range of 30-35psi.

2 questions

1) I am currently ok with it taking forever to make my water but will it decrease the life of my membrane if I continue to run at low pressure or are there any other reasons besides being faster to run a booster pump?

2) the diagrams I see online all seem to have the booster pump after the sediment filter and carbon blocks right before the RO membrane. Is it ok to run it before all of those straight out of the tap or is that not recommended?

KStatefan · Oct 31, 2023

You will also get an increased rejection rate with an increase in pressure.

JayM · Oct 31, 2023

brclark82 said:
I have low pressure getting to my RO membrane, in the range of 30-35psi.

2 questions

1) I am currently ok with it taking forever to make my water but will it decrease the life of my membrane if I continue to run at low pressure or are there any other reasons besides being faster to run a booster pump?

2) the diagrams I see online all seem to have the booster pump after the sediment filter and carbon blocks right before the RO membrane. Is it ok to run it before all of those straight out of the tap or is that not recommended?

1) It shouldn't decrease the life of the membrane. It doesn't pump more stuff through the filter media - just does it faster.

2) Plumbing the pump after the first stages prevents having particulates go through the pump, possibly causing increased wear and/or flow restriction.

Buckeye Hydro · Nov 14, 2023

The movement to put the pump after prefilters was something we started, and it was the opposite of what was standard at that time. Realize that the weakest part of the entire system in terms of ability to withstand high pressure is the clear housings. So if you put the pump after the prefilter housings they never see the elevated pressure, and you can crank up the pressure on the pump.

With your low pressure, most of your feedwater is going down the drain, and very little of it is being converted to RO water. As mentioned above, your rejection rate is adversely affected with pressure that low. Is there some reason you are avoiding getting the pump - it really is what's called for in your situation.

Just by chance... how is the system tapped into your plumbing to get water to the system?

Buckeye Hydro · Nov 14, 2023

brclark82 · Nov 14, 2023

I appreciate that info @Buckeye Hydro , it’s helpful.

The only thing keeping me from adding a booster pump is cost to be honest. I don’t pay for water for the waste isn’t a huge issue for me, although I suppose less waste would be better but at my usage I doubt it matters.

I only make about 50 gallons or so per month so the rate of production also really doesn’t concern me. I have a 35 gallon trash can that I fill around once every 3 weeks or so and my current system will fill it in around 18 hours or so which is perfectly fine for me.

Was more curious if the membrane wouldn’t last as long under lower pressure or if there was some other reason to get the booster pump.

I will probably add one at some point just trying to learn more about it

Buckeye Hydro · Nov 15, 2023

brclark82 said:
I appreciate that info @Buckeye Hydro , it’s helpful.

The only thing keeping me from adding a booster pump is cost to be honest. I don’t pay for water for the waste isn’t a huge issue for me, although I suppose less waste would be better but at my usage I doubt it matters.

I only make about 50 gallons or so per month so the rate of production also really doesn’t concern me. I have a 35 gallon trash can that I fill around once every 3 weeks or so and my current system will fill it in around 18 hours or so which is perfectly fine for me.

Was more curious if the membrane wouldn’t last as long under lower pressure or if there was some other reason to get the booster pump.

I will probably add one at some point just trying to learn more about it

Roger. At a minimum, measure your waste water to purified water ratio when your system is operating and spend $4 on a tighter flow restrictor. By restricting waste water flow more (to something like a 4:1 ratio assuming you don't have a softener), your pressure @ the membrane will rise. https://www.buckeyehydro.com/capillary-flow-restrictors/