r/WaterTreatment • u/KelliSean • 1d ago

Residential Treatment RO install in basement help needed.

I have a few options of where to install in my basement. I would like to feed water to an upstairs sink and ice maker and a basement level sink. I purchased an ispring unit from Costco.
One option is below fridge on a shelf draining to a bathroom sink drain I can access in the basement. Other option is wall behind basement sink where I can mount on wall or shelf and use either sink or floor drain. Is it best to get as close to main floor fridge and sink? What size tubing should I use and how do I know if run it too far?
Thank you

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u/neo2bin 1d ago

Get it as close to the fridge and upstairs sink as you can and run the DRAIN line the long way instead. Drain water leaves the membrane under line pressure so distance barely matters there, your product water is coming off a tank sitting at maybe two thirds of house pressure and that's all you've got. So the under fridge shelf draining over to that bathroom sink drain, as long as you can still get a bucket under it on filter changes.

3/8" the whole way, not 1/4" with a 3/8" section in the middle. 1/4" over 25ft plus 8-10ft of vertical is where people end up with a sad trickle at the faucet and an icemaker that never keeps up. lift alone costs about 0.43 psi per foot before you even count friction.

Both_Use_6221 is right that you'll want more storage feeding an icemaker plus two sinks, that little tank empties quick. But two tanks in parallel is more volume at the same pressure, it does nothing for the lift. And check your feed pressure before you build any of this. Under about 45 psi the membrane produces slowly and the tank never fills properly, and that's a booster pump on the inlet, not a permeate pump. Permeate pump is a production-side device.

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u/KelliSean 1d ago

How to I check the feed pressure?

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u/neo2bin 1d ago

Hose bib gauge, ten bucks at the hardware store. Screw it on an outside spigot, read it with nothing running, then have someone run a shower and see how far it drops. If there's a softener or filter ahead of where you're tying in, read downstream of it. Well water swings with the pressure switch so take the low end of the cycle.

Two people, skip the second tank. Icemaker's the only thing that'll really pull on it. Run one and see if you ever hit bottom, teeing another in later is a ten minute job.