RO/DI pump

[APBorisov]

I tried giving it a search, but the results weren't all that conclusive.

Is it necessary to use a pump for a 5-stage RO/DI unit? I've heard that if your water pressure isn't high enought that it makes the unit not as efficient. The only problem is, when I price them out, they're hundreds of dollars, and that isn't going to fly yet.

Any opinions on the matter?

[goda]

if your psi is bellow 50 at the membrain housing then yes i would use one

they are only usefull if you have high resistance on the outflow ( pressuretank) have low psi ( bellow 60) or need more gpd ( increase psi to 85 on a 90 gpd membrain and you should get about 130 gpd at the cost of more TDS)

inother words... odds are you dont need it even if your psi is low the membrain is still making clean water ( if not cleaner) but will just make less

[APBorisov]

Is it true that if the pressure is too low, then the water quality won't be as high?

[meche]

I bought a cheapie from ebay. It works great although I do not have a TDS meter to check its output. I live in a old house and it has very low pressure compared with todays standards. For example, the guys that came to pressure wash the house couldn't use my water, we had to use a neighbor's supply. So, IMO a large majority of people don't need any kind of booster pump.

"is it true that if the pressure is too low, then the water quality won't be as high?"

Sorta, it is my understanding that as supply TDS increase pressure must also increase to compensate. But this does not mean that if pressure is low then you will end up with dirty water, only that if it is very dirty to begin with you will end up with dirty water. Again, IMO, unless you have terrable tap water and horrable supply pressure, I don't think you need to worry.

[goda]

i dont think so i think it just slows down the production
since from what i seen. pressure higher then the rated makes it worse then bellow ratedpressure


i guess its cause there isnt as much pressure to push stuff throu the membrain so it may be purer.. i dont know a real expert is bound to chime in soon