Does Reverse Osmosis Waste Water? Understanding RO Efficiency

Wasting water is one of Reverse Osmosis' biggest kept secrets. Come along with Master Water Specialist John Woodard to learn about how much water RO systems send down the drain, how the efficiency of an RO system is measured, and what features to look for in an RO system to minimize water waste.

[tomterrica]

The best explanation I've ever heard about RO efficiency. Thanks!

[tommcelroy]

This really opened my eyes. In 2021 I had a new ClearFlo RO system installed. Today did an experiment. I pulled the drain line out of the drain and placed it in a bucket. Ran the faucet to withdraw various water volumes, from 1/2 gal to 1.5 gals. In each case, I got 16% efficiency. For example, when I withdrew 1 gallon, the system refilled the tank, but also flushed 5.25 gallons down the drain.

[lym]

You can add a permeate pump to any RO system to get better efficiency. For example, I bought the Apec RO-HI and added a permeate pump and a 6th-stage alkaline remineralization filter. Because the Apec RO-HI was on sale, it was cheaper than buying the Apec 5-stage RO-Perm that comes with the permeate pump, and I still would have had to add the 6th-stage filter. The permeate pump you want to use is the ERP 1000.

[JustinL-yt]

Thanks for your unbiased knowledge. I've been researching softeners and ro systems for the last 5 hrs, and your video was amongst most.

[SeanSlavin]

This was most helpful. Thank you. I've been trying to figure out why the drain line kept running. Now I know. As big of a pain it is from now on I'll be opening the tank valve and then reclosing it accordingly.

[QKFTW]

Thank you! Exactly the info I'm looking for

[johnporter]

Twenty years ago, I started with a Watts R/O system. After measuring the amount of waste water produced, I added a permeate pump which Watts sold as a kit. It has worked well for years, pumping the waste water into our hot water system for use. Recently, the old R/O system wore out, and I replaced it with a Watts system with permeate pump included. After a few weeks, it has been working fine, with no water waste either. We live in S. Cal., where water is expensive and not to be wasted...

[fullspectrumtradingco]

Just want to say that this video contributed to me ordering one of your premanufactured RO systems. I recommend ordering the airgap faucet with your unit, and double check that you are getting and AIR-GAP faucet. Other than that, it's a decently easy install. You will need 9/16", 11/16" wrenches or an adjustable wrench at a minimum. They include a hefty amount of PFTE tape, thankfully.

[Handle]

Why do the Neo Pure only have 4 stages when most have 5 stages? And why do the Neo Pure come with a permeate pump but the five stage ones on your website do not have a permeate pump?

[davefowler]

John - One of the key things consumers do not understand is the pressure differential across the membrane is the key to membrane efficiency. [Efficiency Rating will be the new watchword and standard from the EPA for RO manufacturers as they all try to get onboard with the new WaterSense testing and disclosure rules] that emphasize efficiency of a system over its entire production cycle vs. Recovery Rate, which can be misleading as you point out. That's why Permeate Pumps are so helpful with conventional air-bladder systems. By keeping the backpressure felt by the membrane very low (typically it's locked in at 5 psi), the PSI delta P stays as high as possible, because the Permeate Pump "presents" to the membrane only 5 psi -- even as the tank is operating at it's psi peak. Another thing to note for your listeners is the importance of water temperature and the dramatic effect it has on membrane production and membrane efficiency. Remember folks, membranes are tested by NSF at 77F. For every 1 degree less than that you lose 2% of production! When sizing an RO system, consider the NET operating pressure, not just the feed water pressure and the Temperature compensation factor. Add these two together to size your system.

[JWoodcock]

I find myself in a very rare spot right now. I'm sitting with the brand new RO system I ordered, and much unlike my usual self - I 100% missed this glaring downside.

[RafaelSwit]

Can you recommend a whole house filtration product that meets or exceeds EPA WaterSense standards? I’m on a city water. I’m an aquarium hobbyists, so my water usage is a bit higher than a typical household. I’d like to reduce waste water production as much as possible, for both environmental and economic reasons.

[ForxEver]

The best way to maintain the efficiency of the RO system is to use a non-pressurized tank with a float switch...

[johnkrystek]

I use 3/8 tubing for my RO system; will a standard permeate pump be compatible?

[utcast]

What about countertop units that have a tank you fill. Aka no plumbing to a water supply

[Reedith]

What size flow control should be used ?

[TNgo-ginj]

Definitely it wastes the same amount of watered it filtered. For every gallon I filter, it discards a way 1 gallon. I observed it. I m not sure future system can reduce amount of waste water. My system wastes with that level, not the same ratio mentioned in this video. I will check if my new system reduces waste water later weeks or months.

[AlanLogston]

how does the drain water not flow back up into the unit? what if you get a bad clog and both sinks are full causing back pressure?

[wannabelikegzus]

Could you run two or three RO filters at once on the same system and skip the pressure tank entirely? My understanding is that the pressure tank exists to make up for the RO filter's low flow rate. Alternatively, would adding a pump into the system to create higher PSI in the RO filter increase it's efficiency and therefore flow rate?

[lifeessence]

I bought a permeate pump to attach to my RO system in order to conserve water (water rates are increasing FAST!) but am confused as to how to install it. Watched every video I could find and they all are inconsistent, making it even more confusing. Guess I'll have to bite the bullet and hire it out... not sure about the trade off in savings.