Is Reverse Osmosis Wasteful?

Is Reverse Osmosis Wasteful?
By Mark Timmons
More from this author

"Don't even talk to me about reverse osmosis" said the woman on the telephone.  "They waste too much water and I want to be conservative with our water resources!"

That is something I hear quite frequently and frankly, I don't understand it.  Oh, I understand wanting to be conservative with our natural resources, but that same woman was driving 7 miles to town and back to get bottled water which probably was made by reverse osmosis anyway!  Let's pollute the air and waste fossil fuel, but dad-gumitt, I won't waste a drop of precious water! Of course that is crazy, but let me put this in perspective.  A reverse osmosis system wastes about 4 gallons of water per gallon made.  If you use 3 gallons a day for drinking, cooking and internal consumption, that means you will waste about 12 gallons, making a reverse osmosis system about 25% effecient! However, US Water Systems are able to reduce water waste by up to 80%

Is that bad? Like I said, let me put it in perspective.  Do you have a washing machine?  Do you have a dishwasher?  Why do you have a washing machine and dishwasher?  Well, obviously it's to get your clothes clean and to get your dishes clean and sterilized.   How efficient is your washing machine?  A reverse osmosis system is 25% efficient.  A washing machine and dishwasher uses electricity and hot water (which takes energy to heat) and WASTES EVERY GALLON OF WATER THEY USE.

A reverse osmosis system is not nearly that wasteful - no electricity and no wasted energy with heated water. You have a washing machine to get your clothes clean. You have a dishwasher to get your dishes clean. You think nothing of wasting water and energy to get your clothes and dishes clean, and yet you don't want a reverse osmosis system that is 25% efficient to get your water clean? Are you nuts? How long can you live without clean clothes?  You might stink, but it won't kill you! How long can you live without clean dishes?  You get the picture? Your body uses water to cool it and eliminate waste, but you are unwilling to waste a little water to clean your water for internal consumption?   The water you drink sustains your life?  You'll waste water to clean your clothes and dishes, but not to clean your water? You must be kidding!

May 10, 2011
May 20, 2011 at 12:00 PM
Help! My dishes are coated with white 'crud' and cannot get them clean. Dishwasher repair advised not dishwasher but 'hard water' problem. Contact Mermaid Water to discuss as they installed Kinetico 2100F series whole house water filter system in October 2010. Previously had Rain Soft Water Filter System in home since 2000. Due to problems, poor service, etc., replaced it with the Kinetico. I did not have the dishwashing problems until February 2011. Inquiries to Mermaid(Kinectio Dealer) advised me it was due to dish washing detergent formula changes. Basically, advised to purchase water softener or wash dishes by hand! Had water tested by Lab - results: Hardness as CaCO3-EDTA - 179 mg/L RL 2. Spent hours online reviewing all these systems and an more confused than ever! Home - well water & septic tank - 3 baths. Please any suggestions, comments, etc., are needed. Thannks
May 22, 2011 at 8:41 AM
Karon, Try a product called Lemishine and let me know how it works.
May 23, 2011 at 6:43 AM
Are you an idiot?
May 23, 2011 at 12:35 PM
KG, Are you? I just thought I'd ask.
August 12, 2011 at 4:42 PM
What about something like this?
August 12, 2011 at 6:01 PM
Darcy, I have not been impressed with that model. We are a Watts distributor and do not sell it. Check valves, pumps, re-injecting the water into the hot water, etc. The cure is worse than the disease.
February 26, 2013 at 12:03 PM
This article is written in a very belligerent tone. I wanted to learn about how much water is wasted in the reverse osmosis process and, if this article is correct, 75% is truly wasteful indeed. I have municipal water that was of such poor quality that the private company was forced to turn over operations to a state utility agency until such time as it can be turned over to a county or city utility. Customers complained for 13 years before the takeover and the result of the utility’s and the state’s efforts to improve water is one of the highest water rates in the state. We replaced toilets with 1.28 Gallon or less systems and installed very restrictive water saving aerators at the sinks and low volume shower heads. We put in a shallow well to water our vegetable garden and removed 100% of our turf grass (to the irritation of the home owner’s association but with the backing of Florida state law). Each month, our family of four uses about 5,500 – 6,500 gallons of water and our combined monthly water/sewer bill is between $90 and $120. At these rates, any appliance that “wastes” 75% is a problem for my family. Contrary to the author’s argument, we all use 100% of the product resulting from each cycle of the washing machine or dishwasher so the only question of waste is, can we do the same with less water and less electricity? Modern, high efficiency appliances use less water and energy than their old counterparts. We're still working up to the appliances and doing the math for the return on that investment. Maybe then, we can afford to throw out 75% of our drinking water. <strong>The Water Doctor Replied:</strong> Dave, The tone wasn't belligerent - it was frustrated because of people like you who want to compare apples with oranges. The blog was written from the perspective of point-of-use drinking water, but you extrapolated that into what you use in your whole house. I wrote this: <blockquote>"A reverse osmosis system wastes about 4 gallons of water per gallon made. If you use 3 gallons a day for drinking, cooking and internal consumption, that means you will waste about 12 gallons, making a reverse osmosis system about 25% efficient! Is that bad?"</blockquote> So, if you use 3 gallons of water a day, that would equate to 360 gallons per months (12 x 30 days). This is truly insignificant, especially if you are burning fossil fuel to drive to the store and buy bottled water whose bottles end up in the landfill. However, you don't have to waste this water. You can put it on your lawn or garden, so there is NO WASTE! The point is: people waste a lot more water for less noble purposes. What is more important than clean, safe drinking water? Reverse osmosis removes the largest spectrum of contaminants of any water treatment process. If you settle for less, you will be the filter. I prefer that the reverse osmosis system be the filter, not me! If you are that conscious about saving water, you will have no problem recovering every drop that goes down the drain.
February 26, 2013 at 12:03 PM
Yes, the tone is belligerent, but I suppose the 75% figure is accurate. My plan is to drain the water outside of my home and use it to water plants. This won't work on the coldest days, I know. Also, you can buy a system that puts the waste in your hot water line.
September 27, 2016 at 3:03 PM
I was hoping for information, too. But I also found the post to be belligerent and unhelpful. YOUR comparisons don't hold up and sound sadly defensive. I'll go elsewhere to actually gain some perspective and information about RO water and household usage. I think Dave's right! Using water to wash clothes and dishes is not *wasted*. Especially if you use a water wise system...which I do. AND only wash FULL loads. Not the same at all. For the most part, water that comes out of the tap (whether well or municipal) is some of the cleanest and purest water in the world. Very few of us NEED to RO it. And turning 4 gallons of water into 1 is the definition of waste. AND I have an RO system so I am not coming from a place of having no idea what I"m talking about, but I use it very carefully, thoughtfully and sparingly. I hope we all do because water is beyond precious...along with our air and natural environment. They all work together to keep us happy and alive!
September 27, 2016 at 3:03 PM
I agree that the article is belligerent. And ignorant! I don’t “waste” water washing my clothes and dishes, I use it!
Mark Timmons
April 11, 2020 at 11:31 PM
I am sure you can claim ignorance as an excuse for your belligerence. They say ignorance is bliss...
Mark Timmons
September 27, 2016 at 3:34 PM
So when you clean your clothes or dishes with water, you don't waste any water, but when you clean your water with water, you waste water? WOW! You do need to go somewhere to gain perspective and maybe understand the clear and plain meaning of things. And, water that comes out of the tap is <em>some of the cleanest and purest water in the world</em>? I'll have what you are smoking! There's hundreds of more articles like this, but it's a free country and you can choose to ignore the facts... The fact is that Reverse Osmosis removes the largest spectrum of contaminants of any water treatment process and I think it's worth while to waste 5 or 6 gallons a day as an investment in my family's health. You are free to have your own opinion. Have a nice day.
Violet Mendez
September 27, 2016 at 3:34 PM
I agree with you, Mr. Timmons.
March 15, 2017 at 4:07 PM
This is such an incredibly dumb analogy that I'm having trouble telling whether this article is a parody. You aren't comparing apples to apples. This is even beyond comparing apples to oranges. It's like comparing a car's use of gasoline to a leaf-blower's use, and then stating that the car has better mileage efficiency. Why not compare the car to a truck, or even a different model car? The point is, you're supposed to be comparing RO filtration (25% efficient) to other methods of filtration (nearly 100% efficient).
Mark Timmons
March 15, 2017 at 8:02 PM
Well, thank you Nathan. I will not call you dumb, but you just have bad luck when it comes to thinking. BTW, is that that you in the picture - you look smarter than I pictured? Actually, the point is: <strong>Reverse Osmosis removes the largest spectrum of contaminants of any water treatment process.</strong> Comparing Reverse Osmosis to filtration is like comparing a Big Mac to Kobe Beef, but you probably don't get that either. It's just bad luck.... I tell you. Have a wonderful day, smart guy!
December 18, 2017 at 9:50 PM
So.... what is the quality of RO waste water filtered through a gravity feed water filter? Does it make sense to purify the RO waste water?
Mark Timmons
December 19, 2017 at 9:07 PM
... and then what about that waste water? ... and the waste water after that? But, you can't make RO water without pressure, so there really is no question here and no answer.
Chris Ringer
December 26, 2017 at 3:02 PM
Mr. Timmons, Like others, I clicked through to this article to understand how much water is wasted to produce RO water. In a water-challenged state such as California, it is my duty and desire to limit the amount of water I use and, especially, waste. Like others, I find your tone belligerent and your rationales lacking in common sense. Regarding your comments about dishwashers and washing machines, water is not "wasted" performing these tasks, it is used. Some dishwashers and washing machines are less efficient than others and can be considered to "waste" water. According to a brief search, the average dishwasher uses less than 6 gallons per cycle, while an Energy Star rated dishwasher can use as little as 3 gallons per cycle. So, compared to an efficient dishwasher, an inefficient dishwasher wastes as much water as making 1 gallon of RO water (6-3=3). According to another brief search, washing machines use anywhere from 8 to 40 gallons per same-sized load. The great variation results from the variety in age and of models of washing machines. However, modern machines range between 8 and 17 gallons per load. So, compared to an efficient washing machine, an inefficient machine wastes as much water as making 3 gallons of RO water (17-8=9). Let me put this in perspective: Rather than make 1 gallon of RO water, I could wash a load of dishes with no waste at all. Likewise, rather than make 3 gallons of RO water, I could wash a load of clothes with no waste at all. Regarding your comments about wasting gasoline to purchase RO water in town. In your blog, you state the woman drives 14 miles round trip for the water. In this example, we don't know whether that is the only errand the woman makes, nor do we know whether that trip results in her buying only 1 gallon of RO water. A reasonable assumption is that she combines the RO water trip with other errands. In that case, there is no wasted gas. Another reasonable assumption is that the woman buys more than 1 gallon per trip; more likely she is buying multiples of 5 gallons. Even assuming a single errand trip, the purchase of only 5 gallons, a terrible 15 mpg fuel efficiency, and a cost of $3.00 per gallon of gas, the cost to the woman for that errand is $0.60 per gallon of RO water. This can be considered "waste". However, the moment she combines the trip with another errand, the waste cost goes to $0.00 per gallon. Regarding the math you used in your blog. You wrote, "If you use 3 gallons a day for drinking, cooking and internal consumption, that means you will waste about 12 gallons, making a reverse osmosis system about 25% effecient (sic)!" Efficiency is based on the total amount used. In your example 3 gallons of RO water are produced and 12 gallons of waste water are produced. 3 gallons RO + 12 gallons waste = 15 gallons total. 3 gallons RO / 15 gallons total = 0.20 This means your efficiency is 20%, not 25%. It is unclear whether you are an employee of US Water Systems. However, since you write a blog that is published on their website, the implication is that you are. As a voice of the company, what you have written, and how you have responded to comments, has resulted in the loss of a potential customer. More than that, I shall be escalating my dissatisfaction to US Water Systems' customer service department.
Mark Timmons
December 26, 2017 at 8:03 PM
I guess math is not my strong suit. <strong>Five out of four people struggle with math.</strong> While you are nitpicking and applying the word "waste" as you see fit, I happen to take it as the face value of the word. You seem to think that because your washed your dishes, it is not waste. You could use an ultrasonic device and heat to clean your dishes, so if you elect to use water, you ARE wasting it. The same is true with your clothes. You could have them dry-cleaned and thus waste no water, so contrary to your assertions, it is "waste." Where does the water go? Down the sewer as "waste." I guess I value the water I put inside my body as much as I value to water I use to wash my dishes and clothes. A dishwasher wastes water, a washing machine wastes water and a Reverse Osmosis Systems wastes water, but according to you, RO recovers 20% of the water it uses. How many gallons of the water do your dishwasher and washing machine recover? <strong>By the way:</strong> As we speak, we are developing an RO system that is 50% efficient for under-sink applications and our whole-house systems are now 80% efficient. Thanks for correcting my math!
steve papacostas
December 26, 2017 at 8:03 PM
If RO (waste 4 gal to make one) system is such good at filtering water, why does it need the additional three filters, and the recuring expense, for?
February 5, 2018 at 3:26 PM
Good luck with trying to educate a public that voted for the "lesser of two evils"!All things being equal, efficiency is determined by the incoming water temperature. Here in Florida, my incoming temp averages 85 degrees. My .08 - .10 cents per gallon drinking water (including the cost of my wastewater) is cheap. I use a 15k gallon chloramine filter before the RO system to maximize membrane life. Some communities now use separate return systems to use grey water for gardening etc. Now that's conservation!
February 19, 2018 at 6:07 PM
What an interesting discussion. Thank you to all the contributors. You have highlighted so many of the issues surrounding what we mean by "waste". I am new to RO and recently installed an "under sink" unit in our kitchen. I was surprised to see there is a connection to the "waste" pipe and to hear the dripping of the excess water down the drain. I wonder if the "waste" water could be diverted to a holding tank and used for watering the garden. Why not? That might ease the concerns of those who have a limited supply of water (and the minerals we have removed may be appreciated by the vegetables and flowers.)
Mark Timmons
February 21, 2018 at 9:28 AM
It absolutely can!
February 22, 2018 at 3:42 AM
Chris Ringer's reply is good. Mark Timmons, your logic has flow. I hope you realize, only 2.5 to 3% of earth's water is "usable". All the water (& other base material) that we see today was created millions /billions of yrs ago when earth was created. Earth has been recycling & using it. There was not much of the "waste" since one would need to visit well, pond, river etc to fetch/use the water.. so only required water was used. Now that it comes to our houses directly, we need to make wise decisions. All across the world, there is an increasing shortage of usable water. In my language, we use word "Jeevan" which literally means life. We can not be without water. Consider that you waste 12 gallons a day. In a city with 100 k population the waste would be 1200K in a day. 36 MGallon in a month. imagine what would happen in a year in one city. Hope, u will get volume of the problem. And yes, there are places where they have to find alternative means for washing clothes, utensils, bath due to scarcity of water/ reduce frequency. If we want to avoid such scenarios (& worse) - it would be better to think & act wisely now. What I am stating is pure facts. I have been studying on this academically & know these details.
Michael Hanson
March 3, 2018 at 10:55 PM
Hmm, so the logic is, if you are already wasting water on other appliances, why not waste some more for your drinking water? Hopefully installers offer a way to catch the water for reuse outside or for cleaning. 75% waste is a lot. If you had the waste water pouring out the main faucet the same time as the reverse osmosis unit, I think many people would be disappointed.
Mark Timmons
March 6, 2018 at 3:30 PM
<strong>Well, that is not the logic.</strong> The logic is that water used for drinking is vitally important, and if you use water to wash your clothes and dishes, why in the world would you be opposed wasting a little water to support your life? That said, there are ways to minimize the waste and we encourage that!
March 12, 2018 at 5:05 PM
I support the argument about volume of water used. There’s precious little logic in thinking about your or my usage when our country alone has millions of users. Tell us any NEW ideas you have for water conservation.
Mark Timmons
March 12, 2018 at 5:22 PM
I specialize in water treatment, but I do try and balance conservation whenever possible. OK, I'll give you a <strong>NEW</strong> idea on water conservation: Why do some people lose their freaking minds over wasting a couple of gallons of water a day in order to purify their drinking water to maintain their health and think nothing of running their dishwashers just to keep their dishes clean? There are other ways to clean your dishes other than with water in a dishwasher, but for many contaminants there is no better method to purify water than reverse osmosis? Myself and many others value their health higher than their dishes.
eric jones
March 14, 2018 at 6:47 PM
this needs to be taken offline. a url of uswatersystems telling people its a good idea to dump 3 gallons in the septic for a glass of water is unacceptable. im having trouble finding words to describe how bad this is. as a few have said clean water is an undeniable requirement for mankind to continue as a life form and we already have about 7 billion people more then are planet seems to comfortably support. This artical makes it appear as the us supports wasting water, go to northern California and tell the farmers you having fancy pants drinking water is more important then civilisation continuing, as they are individuals already struggling from drought i expect you will get a nice quick educational exorsice, including one hell of an ass woopin. the example showing all drinking water being ro in one city will take the water needed to feed millions of people should q you in to the severity of this issue and how a single artical online that seems offical from its source page could in fact cause as much suffering as a country going to war. war over water is already a part of are world.....its endless. if some sales man told me some shit like this i would lose my shit. right there in public with the goal of it being as publicly witnessed as possible, and i hate being noticed in public litterly run from cameras.
Mark Timmons
March 14, 2018 at 6:54 PM
Eric, You need to get a grip on reality. Who said you have to waste 3 gallons of water for 1 glass? That is unacceptable and it is also fiction. Efficient RO systems make 4 gallons for every gallon wasted and the waste can be reused, so come on back to reality. Don't make stuff up and don't put words in my mouth. It doesn't make you look smart.
Ron Smith
March 23, 2018 at 10:48 PM
This is ridiculous. These "experts" are using ridiculous arguments for wasting water. So, we are supposed to add yet another way to waste water, besides the dishwasher and the washing machine? That's not a reasoned argument at all. Reverse osmosis should he illegal.
Mark Timmons
March 26, 2018 at 6:05 PM
Ron, Why are you so fixated on this? Do you wear jeans? Do you know that to make a pair of jeansd up to 1,800 gallonsd of water are wasted? You better go naked, dude or you are a hypocrite! Do you drink milk? It takes up to 2,000 gallons of water to make a gallon of white milk! A loaf of bread requires about 240 gallons of water, and a pound of cheese takes about 382 gallons. So a simple cheese sandwich takes about 56 gallons of water. Throw in a small bag of potato chips at 12 gallons and you just ate about 68 gallons of water. Add some turkey and it jumps to 160 gallons! The only argument lacking reason is yours! Give it a rest. You have no argument.
Ron Smith
March 23, 2018 at 10:51 PM
It's 3 gallons of water wasted for every gallon used and depending on how you use it, it can be far worse than that.
Mark Timmons
March 26, 2018 at 6:01 PM
Ron, The amount of waste depends upon the system. Some are 3-1, but we have systems that waste 1 gallon for every 4 gallons made.
March 29, 2018 at 6:59 AM
I too originally thought that the tone was a little flippant, but reading through these comments I get the point. Yes there is some waste, but there are ways to use the leftover and in comparison it does seem worth it. I drive a hyrbid and conserve when I can. I too thought about getting 5 gallon jugs of water while I was at store shopping , but it doesn't seem to make sense. So I load 4 -5 gallon jugs drive home and feel like hooray I'm getting clean water and not harming environment. But if I do that couple times a month I have used more MPG carrying that load and adding to landfill. Also as mentioned if that water I'm so happy buying or refilling jugs was made from RO in the first place I'm really not helping. I think point he is making is we wash our cars in the car wash without a second thought, or some brush their teeth with water running, or taking longer showers or running water while shaving, or leaky toilet, faucet or a myriad of other ways we waste water with 0 actual benefit. In that case drinking water that is going into my body, an actual good case makes no sense to balk at, considering. I'm sure some will disagree and then go water their lawn to keep it bright green etc etc, but if nobody has a better idea or alternatives not really a point in attacking the author.
Mark Timmons
April 1, 2018 at 2:25 PM
Thanks Mike, We are always trying to conserve water, but some people just lose their minds over nothing, so I just give it back to them.
May 19, 2018 at 8:59 AM
I really just wondered what the ratio was because I didn’t believe it was as high as I was told (turns out it’s higher). We took out the RO and replaced it with an eSpring, since it uses 100% of the water, has UV technology, and has a higher clean water rating than the RO.
Mark Timmons
May 19, 2018 at 9:46 AM
How do you like the warm water? How much do you have to run until it cools down? UV consumes energy too and over time, the fittings become embrittled from the heat. Watch for leaks. Since RO removes a much larger spectrum of contaminants than any other process, there's no way filtration can have a higher clean water rating. It's scientifically impossible!
May 20, 2018 at 1:05 AM
It’s not warm... so I’m not sure what you’re referencing. I saw online that older models had the light on all the time so that may have made warm water?
Mark Timmons
May 26, 2018 at 3:37 PM
That's funny. If the light is not on all the time, the little critters can just swim on past it. Good luck with killing the bacteria.
June 14, 2018 at 10:52 AM
The point many are missing related to the scenario of traveling to purchase RO water is that the “store bought” RO water ALSO required 4 gallons of “waste water” to make each clean gallon. The woman in the hypothetical scenario isn’t saving any water at all. It’s a choice of personal preference; I can’t imagine not having a system here in the AZ desert, even with the extreme need to conserve. We rely on our RO system to provide clean, safe water for consumption, ice production, and use it in the humidifiers as well. We currently divert much of the “waste” water to our landscaping, ant the native plants seem to thrive on it.
August 24, 2018 at 11:58 AM
I have never seen so many idiotic comments in one place. Mark you may as well just give up. Let these people just go buy bottled water and be done with it, they will never get it.
August 25, 2018 at 5:30 AM
Is RO wasteful? Well humans are wasteful. We are animals adapted to using and consuming our environment. The problem with this post is that valid arguments and bad arguments are presented as equal, which is triggering people. As a fact people need to wash clothes as a health issue, even more so wash dishes. The pathogens in both present not only a very real danger for yourself and family but is a public health issue. Travel to India or SEA where hygiene on these very issues are not to first world standards and immediately this is an asinine position. So you do need to wash dishes and clothes. This logically establishes that such activities are necessary uses of water and thus by definition do not constitute “waste.” Now do you NEED RO water? There are obvious benefits but from a heath perspective you will not generally not get immediately sick from a pathogen and/or spread it to your kids or community because you drank municiple water. This is where ppl are getting stuck on. Logical fallacy invites challenge. Back to the original question, is RO wasteful? Assuming that one would purchase bottled water, no not really. Since bottled water Is often RO. If the comparison is to filtered water, then yes you could make that argument. Then the argument defaults to “do you *need* RO water” as opposed to carbon filtered and it comes down to a benefit-cost argument. RO is definitely superior it does use more water but if you take care to turn off the water brushing your teeth and unnecessary flushes, doing dishes you can get much of it back
September 18, 2018 at 8:42 PM
Mark Timmons is obviously an angry, biased, idiot who doesn't understand that water will soon be more expensive than gasoline. We can create new, and more efficient energy sources, but water is finite. Also, using the waste water from the osmosis process outside to water plants is crazy. The sodium is exactly what many plants don't care for (if anything, put it in the ground; it'll get back to the aquifer). I'd say he's a water 'charlatan', not a water 'doctor'. Never seen so many excuses from an 'expert' to avoid the ever more important concepts of conservation of all natural resources. You just convinced me to stay with my Brita pitcher, and avoid your wasteful, expensive nonsense.
Mark Timmons
September 18, 2018 at 8:55 PM
It has been my experience that people who call others " an angry, biased, idiot who doesn’t understand..." and a "charlatan" have some very deep-seated problems and should seek some psychological help or medication. If you think a Brita pitcher will remove many contaminants, you are delusional. I would advise you to get more education about plants, sodium levels and many other aspects about water. I'm not angry at you and I hope you seek help to get better. Good Luck.
Guy Stocker
October 17, 2018 at 10:40 AM
Thanks every one for all your arguments . Was a good read and very entertaining. I was upset to find out about the wastage after I had bought the system only a week ago . But just as shocked that our government allows these systems in our country. you see here in South Africa we get what you call water restrictions , so you may even go days with out water in certain areas. so you end up going thru 6 gallons a day with your family , ( making food , brushing your teeth , washing your face , make a cup of coffee.wash the dishes all with that 6 gallons), So what may be waste to one may not be waste to another . But thanks to all the clever people here I will now get a holding tank for the waste water and a pump connected to my washing machine and dish washer and use the RO waste water to do the cleaning work. Then my family can enjoy their 3 gallons of RO water a day while I knock back a few beers with some Rum and Coca cola, Because only drinking RO Water for the rest of my life so as not to use my body as a filter is what I call a "Waste " of life. But thanks guy's and girls for your combined input I will defiantly do the tank (pump) set up with the waste water . Even Thou the tank system will now cost me more the RO system :( regards, Guy Stocker
Josh McCoy
January 27, 2019 at 10:23 PM
Great article. Answers my RO question (about efficiency). I actually have 2 previous systems from you guys. It’s funny how everyone here is getting bent on your tone, but missing the point. Thanks Mark!
January 28, 2019 at 9:03 AM
Hi Mark, You could make the RO 100% efficient instantly by connecting the reject water outlet to the toilet flush tank. That way, the reject water will be used to flush toilets, thus won't be "WASTED", but rather used "efficiently", and all the people not getting IT, will be happy. Just combine RO with toilet flushing system and rake in the big bucks. BTW, these zero waste systems will fill landfills with used RO membranes. I wonder what the environmentally "conscious" folks have to say about that. Also, thanks and kudos to US water systems to allow you to speak your mind, even if abrasively towards certain people. In today's corporate limitations, such is a rarity. Many lives are lost to unclean water even today. I rather save the sick time or death and "waste" some water - than the other way around.
February 3, 2019 at 9:52 AM
We had the film in the dish washer, and film in the showers. Installed a water softener for the whole house and have a 20 GPD reverse osmosis under the kitchen sink just for drinking water. We use about 1-1/2 gallons of drinking water per day, so our 'waste" water is about 4 gallons per day which we collect and put on our garden and house plants. We have no more films, and our drinking water is superb and registers about 3 ppm of dissolved solids, close to distilled! We are very happy with the setup and would recommend this solution to all.
February 11, 2019 at 6:47 AM
I m using it to clean windows. What an absolute wast of water. My garden got watered fair enough. But I'm chucking a way more than I use. WAST.
Mark Timmons
February 11, 2019 at 11:47 AM
What kind of system do you have? I have found that most window washers have their own "homemade" systems that are about 15% efficient. That means they waste a godawful amount of water. You may be wasting 6 gallons for every gallon made. That's why smart window washers use our engineered systems which waste just 1 gallon for very gallon made. You should consider the benefits.
March 18, 2019 at 2:50 PM
Thanks for your insights. How "contaminated" is the by product from RO? Could it be utilized for non-potable functions such as clothes, dish and sundry other cleaning functions? Lawn and garden irrigation systems? I assume no problem passing through a toilet system and entering the drain field?
Mark Timmons
March 25, 2019 at 10:54 AM
Yes, it generally can be utilized for all that.
April 19, 2019 at 11:44 AM
YUP Agree with the Doc ! If you believe the waste theory and it bothers you that much! Save that "wasted water" to put on your garden the plants will enjoy it! or flush your Toilet with it! still think RO is worth the effort and "waste" ! just me! There are other solutions if you are inventive!
June 2, 2019 at 12:11 PM
Hi, this might be helpful in regards to ro efficiency. Ro membranes are rated at different efficiencies, so start off with a low waste model. Mine is 1:1 (1 volume of drinking water:1 volume of waste) The major efficiency problem with RO systems is the storage tank, which is usually pressurized. The fuller the tank gets, the more pressure is required to fill it. I don’t know the exact calculations but efficiency seems to decrease exponentially as the tank fills. For example, I have a 12 litre storage tank. When filled from empty (allowing it to fill completely without drawing water from the faucet), the waste produced is about 17 litres. However, if I draw 1 litre from the full tank and allow it to refill, there is about 5 litres of waste water produced. I have my waste water line connected to storage containers which is why I know this, and I’ve tested it a few times. So, what I do is allow the clean water storage tank to fill completely, and then turn off the input water valve. I then use all of the water from the tank before turning the input water on again. There are other factors which can decrease efficiency - colder water is less efficient, lower pressure mains water is less efficient, and the more head or height from the ro system to clean water container and waste container or drain will decrease efficiency also. These are very small decreases though, as long as input pressure isn’t under the manufacturer’s guideline and output head or pressure isn’t huge (shouldn’t be more than 50 cm in most undersink situations so negligible also.
Mark Timmons
June 4, 2019 at 6:23 AM
There are not as many differences in membranes as you think. 1:1 or 1:4 or 4:1 waste to production ratio is dictated by the water quality, not the membrane. The rest of your post is correct.
September 19, 2019 at 1:51 PM
3rd paragraph, 3rd sentence: if you use 3 gallons and waste 12 gallons then there are 15 total gallons involved. 3/15 is 'about 20% efficient' ('25%' is incorrect) since you need 15 gallons (NOT 12) to get those 3.
Mark Timmons
September 28, 2019 at 11:24 AM
5 out of 4 people struggle with math.
hard water stains
November 1, 2019 at 3:03 PM
Yesterday, while I was at work, my cousin stole my apple ipad and tested to see if it can survive a forty foot drop, just so she can be a youtube sensation. My apple ipad is now destroyed and she has 83 views. I know this is completely off topic but I had to share it with someone!
December 1, 2020 at 10:45 AM
my home has 1500 parts per million coming out my well, i have a whole home RO and and iron buster system. most the time its my wife and i, but we have kids that are in and out for about half a year so its like a family of 3 really. my water coming into the house at 14 PPM now. i "lose" not "waste" 75% of my water in the process, i call it lose because the water is not destroyed, it goes right back out the house into the yard and thus back into the system where the soil filters it back in the natural system or it evaporates and comes back as rain. RO systems are not about waste, they are about clean water and if you NEED it, you pay the cost. i cant drink our water out the well as we live near the coast in Florida and have saltwater ingress into our wells. since i put the system in my appliances are not rotting in my home, the fixtures are not caking up with scales and our glass show never needs rinsing. maybe an RO is not for everyone but it certainly made the quality of life in our home so much better that returning 3 gallons of water to the system for each i keep is price i am willing to pay. i mean seriously what did some of you think happens to the "waste" water after your done with it? its not gone just on its way back where you got it from in the first place, be it the ground our the city's waste water reclamation plants which means you did more harm driving for water them creating it yourself.
December 1, 2020 at 10:47 AM
shoot i forgot why i was posting, i was looking for information on a dry wells size to put wastewater back in the ground without putting in on top the ground, anyone do anything like that here?
Mark Timmons
December 1, 2020 at 11:17 AM
Ed, that is an environmental issue. You would have to contact your State Agency to determine if that is appropriate. However, with that level of TDS, I would prefer (personally) not to put it back into the ground.
December 1, 2020 at 2:24 PM
Not sure what to do with it then, i took it out the ground and have no city sewer, right now its just evaporating or going to the storm runoff. its mostly salts, sulfur and other hard water stuff, without the salt and i am standard hardness and of course the sulfur is removed in an aerator tank . the problem is it keeps my yard wet around the ditch and i get stuck on my mower and cant get the boat across it. I know were allowed to french drain/dry well grey water out here i just dot know how big to go. is there any reason not to push it into the septic?
Mark Timmons
December 13, 2020 at 10:57 AM
You can certainly try it. I know lots of people who do. It’s just a simple matter of whether your soil will accept that amount of water. It is worth a try. If that doesn’t work, I would suggest making a large French Drain. Some people take five or six 55 gallon barrels and cut the ends out, burying them and filling them with gravel. Good Luck!