Does whole house reverse osmosis make sense?
The short answer is "YES" but that doesn't mean that it is for everyone. We will consider the pros and cons of a whole-house RO system and you can decide if it is for you or not. First of all, water quality varies greatly from well water to surface water to municipal water. Well water may have things like iron, sulfur, manganese and tannin which almost always have to be removed, especially in the case of a whole-house RO system. Those contaminants must always be removed before the reverse osmosis process. Let's not forget that reverse osmosis removes the largest spectrum of contaminants at the most economical cost of any water treatment process. Essentially, a whole house reverse osmosis system will remove 98 to 99% of most contaminants including Total Dissolved Solids (TDS), sodium, chloride, sulfate, nitrate, arsenic and a plethora of other chemical and organic contaminants. One of the key ingredients to a whole house reverse osmosis system is proper per-treatment, which includes removing the iron, sulfur, manganese, tannin and other nuisance elements. So, ahead of an RO system, it is essential that filtration or oxidation of these contaminants are accomplished. If the water is hard, then it needs to be softened or (what I prefer) use an anti-scalant to prevent hard water build-up on the membranes. Anti-scalant systems are gaining popularity because no water is wasted and no salt is needed. A whole house RO system consists of the aforementioned pre-treatment, the reverse osmosis system itself, an atmospheric storage tank, a re-pressurization pump, ultraviolet light or Quantum Disinfection and sometimes a calcite filter to raise the pH or add some TDS back to the water. Here is what a city water whole-house RO system might look like:
Who might need a whole house reverse osmosis system? Lots of people. It could be health related in that they may want to remove as many chemicals as possible from their water. Many people have a sensitivity to such chemicals and therefore need a whole house RO system. In other cases, it may be that there are contaminants in the water that create ascetic issues such as high chlorides, sodium, sulfates and others. Sometimes we see water that has TDS levels in excess of 2,000 PPM (the USEPA recommends drinking water that is below 500 PPM). I'll grant you that the water you use to flush your toilet doesn't have to be super clean, but the amount of water used for flushing toilets in very insignificant compared to most other uses for water in your home. Washing dishes or clothes, bathing, shampooing, shaving and cleaning in clean reverse osmosis water is a pure joy. Back in the day, people used to bathe in rainwater, which is generally absolutely soft. When I was in Haiti a few years ago, we would wait for a heavy rainstorm and stand underneath a downspout plume just to enjoy a good shower. With shorts on and a bar of soap, we enjoyed every second of that shower. If taking a shower in the cleanest water on the planet, without chemicals, pesticides and hardness appeals to you, then maybe you are a candidate for a whole house reverse osmosis system. If you want to be able to drink from any faucet in the home, then maybe a whole house RO system is for you. Maybe you just want the best water possible. If so, a home whole house reverse osmosis system may just be what the doctor ordered! Cheers!
141 Comments
Mark, I think it is very informative and who cares about grammar. If every 10th person knew about these systems and how to instal them properly this country would ve much healthier. But people are dumb enough to buy bottled water which may be even worse than toilet water.
I just reread the article and couldnt find the mistakes the grammar cop mentioned. So that search was a waste of time. But as for the most important part, the content, it was worth rereading it.
Hi Mark: I live near Flint Michigan where we are having the major problems with lead and contaminates in the water. I want to buy a few houses and put whole house RO systems in to make them safe for drinking and bathing and rent them out. What would you recommend?
Mark, what do you recommend in SoCal where the water is hard? I have a house with 4 bathrooms and 6 people. Should I do a whole house softener and then whole house RO? Do the RO systems waste water? If so, is there a way to capture the wasted water to use for irrigation?
Ken
How do you protect water heaters and other metal components like faucets from corrosion with a whole home RO system? RO water is very corrosive regardless of pH.
Hey Mark,
I have been trying to get a better understanding of RO systems and how they operate and some real technical information on them but information is scarce to say the least. My current system is about 19 years old, but it is still working minus some quirks. The recent problem I have run into is my booster pump failed that is feeding two 2.5×40? membranes. I believe this system is producing a lot more waste without the booster pump working which is causing my well to dry up. I have ordered an ac motor to replace it. (pump is just a 1/2 hp motor connected to a fin hosing) Another thing I would like to do is add a third membrane to my system. Would this produce more water and less waste if I had two membranes connected to the source water and the third membrane being fed off the two source membranes? Im also thinking about changing the size tubing from 1/4" to 3/8". All of the membrane connections are being downsized. I am not sure how this would affect my pressure going in to the membranes though if it would cause a huge issue.
No one around us knows RO systems or is willing to share information, everyone is asking me to spend 3500-4500 on a new system that they can just plug in.
Our Water information:
TDS 1600+ PPM
Chlorides 390 PPM
Flouride 4.53 PPM
Iron 0.21 PPM
pH 8.7
Hardness 1 grain
Current Filter system:
75gallon pressure tank
Carbon cartrige filter in big blue housing
5um Sediment in big blue housing
1um Sediment in big blue housing
(2) 2.5×40? RO membranes
2 150 gallon storage tanks
Chlorine Feeder to storage tanks
25gallon pressure tank w/ booster pump
Carbon filter w/ backwash
Acid neutralizer
Hi Mark, I live in south florida on well water. I have an iron filter, softner and carbon filter. We keep having a white residue on dishes and just about anything in contact with our water. Had a couple of water system companies come out and they wanted to blame it on hard water, but our system checked out to be working fine. Their water test should a high salt content and suggested an ro system, with estimates as high as $ 10,000. We have a 2 bath house with 3 people. What system of yours would you recommend?
Thanks
Mark
Enjoyed reading your comments on RO. Im currently in the market looking for a whole house RO system. The only system Ive seen so far is the one manufactured by Kinetico. Can you comment on Kinetico and provide any alternative systems. I live in the Wilmington, NC area.
Thank You
Ted
Do RO systems remove Fluoride? Thanks.
-Jeff
Would you mind providing a functioning link to the smaller whole house unit which would be appropriate for an RV mentioned in your Jan 22, 2014 answer? How about a semi-portable, partial-house RV system which would be suitable for those who would like to have one RO shower but can not contemplate a whole house system? Please email if you would consider granting a water test in exchange for being featured in an article which would be read by individuals in a city/region with very severe water.
Can these systems be installed outside?
Have a well with high Arsenic III. What would you recommend to oxidize it to Arsenic V before a RO system?
We have had extensive testing done on our well water. How can we get the results to you so we know what system would work with our well water?
We are looking to buy a home that has arsenic and salt in the well water, would you recommend a whole house system?
We have a fairly new well which produces quite a bit of water, but with hard pumping the turbidity increases to very cloudy levels. A nearby well produces very little water at the same depth, but the water is clear. When the new well was bailed during drilling, there was some mud to start with, then very fine sand, then gravels. This bailing was typical all the way to 373. There was a problem area at about 278 where the formation collapsed twice. Welded steel casing had to be used from above the surface to the well bottom. Slotted pipe with 1/4" slots was used from about 250 to 373 since much of that formation produced water. The slots are large, but even smaller slots would not stop the very small suspended particles. This area in the well (278) seemed to be an ancient river bed with boulders, to very fine sand with silt and lots of water. At first use, the well water was slightly cloudy, but became more clear over time. Then, with heavy pumping for hours, the turbidity shot way up. The turbidity appears to be very fine particles of possibly clay, silt, and sand. The particles are so fine they stay in suspension and go right through a whole house sediment filter and right through a carbon filter. A backwashing filter was recommended, but I wonder if the suspended particles will pass right through that filter. Our thought was to only treat the water going to the house. Most of the water is used for trees and gardens. There are no close septic systems and no surface water. The static water level is 216, with some artesian pressure since the first water was found over 240 deep. What do you recommend to get rid of the particles in suspension? Water in this area of the desert does typically scale swamp coolers.