Is Reverse Osmosis Wasteful?

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

Karon, Try a product called Lemishine and let me know how it works.

Are you an idiot?

KG, Are you? I just thought I'd ask.

What about something like this? http://www.watts.com/pages/_products_details.asp?pid=7257

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.

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.

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!

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).

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?

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.

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!

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.)

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.

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.

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.

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.

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.

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.

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.

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.

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?

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.

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.

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

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.

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

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!

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.

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.

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.

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?

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!

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.

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.

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!

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.

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?

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?

I read your article & I found This is really very useful and informative for those people who need to know about it. Thanks for Sharing.

I read your article & I found This is really very useful and informative for those people who need to know about it. Thanks for Sharing.

Does "RO" systems waste water? It's a question pf perspective. Did you "Waste" water taking a shower, or "Use" water to take a shower? I say I "Used" some water to obtain clean drinking water by using a "RO" device; just as I "Used" water to take a shower. I have spent many days investigating different methods of creating distilled water. Boiling water and condensing water vapor is an expensive method, yet does work well. A Solar Still is similar process using the Sun as the energy source, but requires large areas in direct sunlight all day. It is a slow process that yields about 1-1/2 gallons per day in sunny areas. Unfortunately does not work at night. "RO" systems work slowly as well, yet produce 24/7/365. As much as I have the space and plenty of sunlight to make a solar still, the material costs and my time to build it is too much compared to buying 5 or 6 "RO" systems. Besides, a solar still will "Use" or "Waste" some water depending upon your "Perspective"!

I built a water filter system. !st level - 5 micron whole house sediment filter, 2nd level - 12gpm uv system 3rd level - 5 micron whole house charcoal filter At this level the system splits for household purposes and to drinking water filtering system 4th level - 5 drinking water filters 4,250g capacity, VOCs, etc. 5th level - .5 micron drinking water filter 4th and 5th level for consumption, ice and cooking This filtering system has worked for 15yrs to clean the water from my rain water collection system. Total cost for materials approximately $600 Annual filer replacement expense approximately $75. Zero wasted water. I originally installed an RO system not realizing the incredible amount of waste water. luckily I did run the waste to my utility room to a 5gal bucket which allowed me to quickly see the waste water results. I immediately removed the RO system and threw it away. As I live in New Mexico I couldn't in good faith sell it for someone else to waste such a precious resource. I'm guessing a good many people have RO systems are installed for them. And probably don't realize, because most these installations run directly to a drain, how much water is actually being wasted. My system does not treat for minerals but there are water softener systems to remove minerals. Example: EVO Whole House Water Filter and Salt-Free Softener Combo Model number: E-3000. A UV filter can also be added to this system which would eliminate the need for most if not all of the filtering system I built. It's a little pricey but with the current worldwide water shortage and climate change only going to make it worse I believe it is worth the expense.

Much of the most commonly available "bottled" waters are created via RO already. The issue that I haven't seen addressed is the "water cycle". The wastewater output of the RO system is returned to the ground, where the majority of the water percolates back into the water table. I appreciate the concerns of those on "city water" who don't want their water bills to be increased by the amount of wastewater created by an RO system, but the amount of water on earth is a relative constant over very long periods.