How to hook up a R/O unit

[Msand9898]

Ok I just picked waht looks to be a 3 or 4stage R/O unit...
has 2 prefilters & a Postfilter at ther bottom, and unit long unit above...

How do I connect it together..

It appears to be manufatured by King Water Systems in Fountain Valley, CA

[kennerd]

I ran into a puzzling time setting mine, given the fact that there are three line connections to my unit. I figured that there would be only two lines on the system IN & OUT. Not so.

There is a third line, which is the RO membrane's waste line for the waste water that does not get forced through the RO membrane.

If it's a 4 stage (sounds like it) it should be set up as follows:

Inlet line runs from you water source into your sediment pre-filter (stage 1), then plumbing should run from the this to the carbon filter (stage 2), then plumbing to the inlet side of the RO unit on top (long unit, stage 3).

There are two outlets on the RO unit. One is the "waste line". I run mine into a bucket in my slop sink & water my plants with it. The other line should be plumbed to the DI filter (stage 4, or as you called it, the post filter), and then the last line coming from that stage is your purified water.

Keep a few things in mind, that I didn't really know when I set up my unit: RO membranes work on pressure: forcing the water through the membrane, and leaving the junk behind. Depending on how you set up your inlet from the water source, make sure you can turn up to full pressure. My unit is in my Laundry Room, so I just bought a garden hose splitter & installed it on the cold source for the washing machine. Without enough pressure, the water will keep from going through the membrane, and all you'll get is waste water.

Next, the purity, hardness and temperature of the source water will also affect the amount of purified water you will get. During the winter, I was only getting 1 gal of purified water to 3 gal of waste water (which is why I put the waste water bucket in the slop sink: alwaays overflows before I can get back to it), but now, with warmer temps, is rnuning a little under 2 to 1.

Ken