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, 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!


23 Responses to “Does whole house reverse osmosis make sense?”

  1. Erin Berger says:

    Can you provide a cost estimate for the complete system profiled above? My friend is a very capable Hvac engineer who is going to do my install, mainly I am concerned with the cost of the equipment. Thanks for your article and assistance?

  2. Mark Timmons says:


    Here is the link to our systems:

    We have three sizes. How many in your home and how many bathrooms?

    They are easy to install and we are here 7 days a week for tech support.

  3. Kay Baird says:

    We have a well and need to filter out bacteria. We have an under the sink reverse osmosis system for drinking. What would you suggest and cost. Thank you

  4. Kay Baird says:

    2 people. 2 bathrooms

  5. Mark Timmons says:

    I would suggest a full water analysis before doing anything, but likely you will want to use ultraviolet disinfection, like this:

    Here is the water test I would recommend:

  6. John Lindstrom says:

    We have a RV and we will be living in the full-time and traveling all over the US. Not knowing what kind of water we will be getting into, what would you suggest. I’m leaning towards a whole house system with a water softener. Also, do have companies that would install a system or should it be portable as space matters a lot?

  7. Mark Timmons says:


    First of all, we have many people with RV’s come to our facility and have systems installed. We are in Indianapolis, but I have no idea where you are.

    We have a small, powerful softener made for RV’s:

    We usually use some pre-filters like this:

    Typically, we would install this ahead of the softener with these filters:

    #3: (city water) or (this for well water)

    Followed by:

    and this for just at the sink for drinking:

    Let me know if you have questions.

  8. Kathy Feyk says:

    I have a well that is causing blue staining in my sinks toilets etc and also corroding my fixtures. Do you have anyone in Houston, TX to help me? Need help ASAP. Please. Thanks.
    I discovered my email was wrong so resent.

  9. Mark Timmons says:

    No, we only sell direct, but if you get a detailed water analysis like this:

    we can probably help!

  10. Bern says:

    Hello, can hard water not sure whats all in it cause hair loss. My son’s hair has thinning spots in it and mines is thinning at well. I have brown reside on each shower head and on the facet on the sink. It looks nasty. Cause this cause hair loss?

    Thank you.

  11. John Sagert says:

    Hi Mark,

    How often do you have to change out a RO membrane? I know they are pricey items. Also, how do you get rid of the white (lime??) residue that corrodes every thing and anything that is in my home? That stuff has utterly destroyed 2 hot water heaters now in only 17 years, literally rusting them in 2. And God knows how many bathroom, kitchen and outdoor fixtures I have had to replace. It does not bode well for my fish tank(s) and related equipment either. Fortunately my house is plumbed with PEX, but this does not keep the fittings from falling apart and consequently leaking. Again, fortunately all of the fittings are exposed and easily repaired. Would a RO filter economically survive such an environment? I had a under the sink system for 13 years roughly and honestly, it seemed good except the pre and post filters needed replacement way to often and cost a pretty penny. The RO membrane cost so much it was actually cheaper to replace the whole system!

    My water supply is a community well that is tested multiple times a year with a 200 to 400 ppm TDS, and per the state and county exceeds minimum safe use and consumption standards. I have 2 full baths and 3 persons in my home.

    Any advice would be appreciated!

    Note – I am in the market but I research extensively before I do anything. And since I just finished replacing the hot water heater (again), I am attempting to locate a good economical way to clear up the water. I currently use a whole house sediment filter that runs at 1 micron. But again – this does not remove the “hardness”, just large amounts of them.

    John Sagert

  12. Mark Timmons says:


    The RO Membrane can last from 6 months to 6 years… or more, depending upon how well the water is pre-treated (i.e, softened, iron removed, etc.)

    You get rid of the lime with a softener or an anti-scalant.

    You can replace all the filters AND the membrane on our undersink RO system for $55.00 – usually once a year!

    A softener would be the best solution and if the water were softened, the membrane would last years, making the annual filter cost $34.95.

  13. Maureen says:

    I am on well water and have a terrible sulfur smell. We have been putting hydrogen peroxide down the well, which helps with the smell for a short time. we’re having to use it more and more often. We are researching what will be the best type of system for our problems. I really don’t like water softners because I don’t like the salt taste in my water. Can you please send me some information?

  14. Nick says:

    Not to be rude, but it seems to me like Mark Timmons is a salesmen with no experience in water treatment. I know it may be to late for you guys but hopefully this will answer some other’s questions.
    Maureen- your smell is most likely caused by iron or iron bacteria in the well water. Adding bleach or Hydrogen peroxide as you have been will help. If you don’t want to do a water softener, some form of aeration would take care of the problem without chemicals.

    John Sagert- I figured Mark would be of some help on this and corrected you. The white you see is hardness scaling out in the form of calcium carbonate, not calcium oxide or calcium hydroxide (lime). Lime is actually used to soften water believe it or not. All you need for that is a water softener, that will also allow your 1 micron filter to operate more efficiently. An RO system is not needed in your case, but if you wanted extra pure water go for it.

    Bern, I haven’t done any research on this, but I don’t think so. My wife and Mother in law have been on hard well water their whole life and have great heads of hair. The brown residue you see is iron buildup.

    Kathy Feyk- the article touches on this issue, but doesn’t tell you what the effects are. The blue staining is most likely due to low pH water. That is hell on copper. The calcite filter will help with that. I know because I have one! If you click on the calcite filter link you will get some useful info on this.

    Water Treatment Operator

  15. Nick says:

    Haha, just clicked on the water test link… buy this test for $60, BUT WAIT, there’s more, if you buy the overpriced, overkill for your situation water system we recommend, THEN well apply that $60 bucks toward your purchase.

    Haha, come on guys

  16. Mark Timmons says:


    I don’t think you are rude, just ignorant and arrogant! Those two are often a deadly combination. “Salesman with no experience in water treatment?” I don’t need to re-cite my credentials, but my 42 years of experience in treating home and commercial-industrial applications speaks for itself. I have worked with the EPA and other state agencies for many years. You said “adding bleach or hydrogen peroxide will help”. What about the THM’s formed from the bleach and while we are at it, do you have any clue that bleach has additives which are not to be used in potable water? That is very dangerous advice. Then you go on and say “if you don’t want to use a water softener, some form of aeration would take care of the problem without chemicals” Really? Seriously? A water softener will do nothing for the smell! A water softener is not even in the equation – it does nothing for sulfur water. Aeration will handle very small amounts of sulfur, but if you have higher amounts, and also sulfur-reducing bacteria, you can make a big mess. And, while you are at it, why did you not tell Maureen that when you add aeration, you can introduce airborne contaminants (bacteria) that will also have to be dealt with.

    To even comment on John’s water without a detailed water test shows TOTAL IGNORANCE on your part. It’s like going to the Doctor and saying your stomach hurts and expecting him to prescribe a remedy without any testing. That would be felony stupid! The white could be from calcium and magnesium hardness but it could also be the result of high-alkalinity combined with pH issues, high TDS along with chlorides and sulfates, genius! That advice you gave is wrong and morally reprehensible to say nothing of being totally irresponsible!

    Bern’s issue is also one you cannot answer because you really don’t know what is in the water. Only water testing can answer that question. By the way, we lose money on the water tests – we do it as a service to customers because only an uninformed person would try and treat their water without adequate testing.

    On Kathy’s blue staining, it can be from low pH water, but I have seen just as many on water where the PH is above 7.5. It can be a grounding or electrolysis issue and even some types of water problems can cause the blue stains. To say Calcite will solve it is also irresponsible.

    I almost deleted your posts, but sometimes I think it’s good that consumers understand that there are lots of ignorant and unqualified people out there who try and pose as water experts. We are experienced (42+ years) and we test the water, because you can’t treat something properly unless you know what is in the water and if there are any competing contaminants. We take water treatment seriously and are not some hack who just comes in and does a “drive-by shooting.”

  17. Mark Timmons says:

    Again Nick demonstrates that ignorance is bliss and if it is, he must be ecstatic!

    OK genius – tell me how it is overpriced and overkill. Tell me where you can get it cheaper and explain why it is overkill.

    This should be good!

  18. Kenneth Dart says:

    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?


  19. Mark Timmons says:


    Ken, that is a great question… actually several great questions. Whether you use a whole-house water softener or a RO depends upon several issues. Reverse Osmosis removes more contaminants than any other water treatment process and you do need a water softener (and carbon filter) ahead of it or an anti-scalant system.

    RO systems do waste water – so do toilets, sinks, dishwashers, showers and washing machines. It used to be that they wasted three gallons for every gallon made. Now, the newer efficient systems waste one gallon for every three gallons made. That means they are 75% efficient. Your washing machine, toilets and dishwasher are 0% efficient – they waste every gallon they use.

    You can capture the waste water and use it for irrigation if you want. We can help you design a system to do that.

    So, do you want RO water for the whole house? Maybe… maybe not!

    In most cases, I would recommend a Fusion Hybrid Softener which softens the water and also removes the chlorine and chemicals, followed by a reverse osmosis system for drinking water only. Here is what I recommend:

  20. Kenneth Dart says:

    What is your opinion on whole house Carbon Filtration?

  21. Mark Timmons says:

    It’s great, but not the only thing you want to do.

  22. Mark Timmons says:

    Thanks, we recently discussed this and plan to fix it soon.


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