RO prepump?

Packrider · 04-25-2008, 05:01 PM

I see alot of the RO filter sellers state you should have a prepump to up the input pressure to get more out of the RO filter per gallon. Is this needed or are they just trying to sell another piece? I'm going to buy an RO/DI but don't know if I should get th epump or not. The other question is powered or not. One shows it using the drain water as the pump driver. Anybody use or have any experience with these? Thanks.

unclejed · 04-25-2008, 05:38 PM

From my understanding, most municipalities have adequate water pressure. You can buy a Gage to tell you but even if you were a little low where you are, it would just take a little longer to make water. Also, some municipalities water is "less cold" and that helps to make water faster. I bought my 5 stage ro/di from "The Filter Guys" and if you call them talk to Jim. He's very personable and will talk as much as you like. I pick his brain all the time.

Pinantanjohn · 04-29-2008, 01:37 AM

Quote:

Originally Posted by Packrider

I see alot of the RO filter sellers state you should have a prepump to up the input pressure to get more out of the RO filter per gallon. Is this needed or are they just trying to sell another piece? I'm going to buy an RO/DI but don't know if I should get th epump or not. The other question is powered or not. One shows it using the drain water as the pump driver. Anybody use or have any experience with these? Thanks.

If you have over 40 psi and no need to max out the capacity of the system then you won't need it. If the system says it will produce 100 gal/day that's most likely at the maximum pressure of 110psi.

I had a system at my last house (still have it but it's not in use right now) and didn't have the prepump. It was fine. Capacity of 100 gal/day, actual production (never really tested it) refilled the pressure res (roughly a gallon) in under an hour at 40-60 psi, well water, tds 400, ph 8.4, 5 micron prefilter and carbon block.

Basic system should produce more than enough for daily water changes in up to a 500 gallon tank. (5%) or weekly (50%).

You are going to get only a percentage of the input water and upping the pressure isn't going to make it more efficient, just process more water. If you can, capture the waste water for houseplants or other use as the RO system is a huge water hog. If you are paying for your water you will be paying about 800% more for the RO filtered water due to this waste. If you are on a well, I suggest that you plumb the waste from the RO back into the well. Waste not want not... Yada yada...

Just be sure that ther's no chlorine in your water supply. That kills the membrane really fast.

Peace...
John