Reverse Osmosis Systems That Kill Bacteria

Reverse Osmosis Systems That Kill Bacteria
Posted in: Iron Removal
By Mark Timmons
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Everyday, consumers purchase hundreds of Reverse Osmosis systems for the purpose of protecting themselves and their family from chemicals and contaminants such as arsenic, lead, chlorine, pesticides, and high TDS while mistakenly believing that their new reverse osmosis system will also eliminate bacteria - IT WON'T!  Reverse osmosis is not designed to remove bacteria.  In fact, we now know that bacteria can grow inside the tank and that in some cases, such bacteria can be very detrimental to some individuals.  RO tanks can literally become "incubators" for bacteria.. that's scary! It is now being discovered by medical researchers that immune compromised individuals, children with autism, infants and the elderly may have severe health issues when exposed to the bacteria in a reverse osmosis tank.  This is often referred to as Heterotrophic plate count (HPC), which is a method that measures colony formation on culture media of heterotrophic bacteria in drinking water.  HPC is difficult to remove, even with the use of disinfectants.  In fact, it is impossible to remove them all. So, you have a reverse osmosis system to remove contaminants because you researched and determined that RO removes the largest spectrum of contaminants of any water treatment process and now you find out that it can contain significant levels of bacteria which can be just as detrimental as other contaminants, if not more so.  What can you do? Well, some people have put ultraviolet lights after the RO or on the RO to neutralize the bacteria - UV doesn't actually "kill" bacteria - it just neuters it so that it cannot reproduce.  However, having a UV under a sink after a reverse osmosis system is usually a bad idea.  The UV light heats the water in the chamber and transmits the heat through the small tubing to the point that the water may actually be very hot when it first comes out of the tap.  The heat created by the ultraviolet light embrittles tubing and fittings which can ultimately end in disaster (i.e., a flood under the kitchen sink).
The purpose of any drinking water system is to reduce the greatest percentage of each contaminant from the broadest range of categories.  Reverse osmosis is the technology that achieves that purpose dramatically better than any other and now the RO system can kill bacteria too.
Nearly all RO systems have a final polishing carbon filter after the tank, right before the water comes out of the faucet.  Until recently, that carbon, while removing tastes and odors became an excellent breeding ground for bacteria.  However, now we have the new media which literally "sucks the electrons" out of any microorganism that contacts it.  The new Pulsar Quantum Disinfection and Carbon Polishing Filter polishes the water as it leaves the RO storage tank and kills 99.99 to 99.999% of all bacteria. So you now have a choice:  You can use an inline filter with just carbon to polish the water or you can use a carbon filter which incorporates Pulsar Quantum Disinfection Media manufactured by Claire Technologies, and polish the water along with killing 99.99% of the bacteria.  Is that a hard choice to make?  You know what I have in my house!  Any Reverse Osmosis can be retrofitted  with the new Pulsar Quantum Disinfection Cartridge, or you can buy a filter pack which also has the Pulsar Quantum Disinfection Cartridge. At US Water Systems, we make sure that EVERY reverse osmosis system is equipped with the Pulsar Quantum Disinfection Cartridge and insofar as I know, we are the only company that does that.  That's one of the main reasons you can trust your water to America's Water Company!
April 16, 2017
Mark Whitnell
June 22, 2017 at 1:12 PM
Mark, good name...I am designing a new RO system using a 4040 membrane. My well water has H2S and Tannins, but no Fe. I am using an aerator from the well to release a good deal of Sulfur, then the water goes into a media vessel that has a mixture of various resins that removes more Sulfur or polishes. Then the water goes into a muliti-stage booster pump then into the RO membrane...I am planning on using 4 solenoid valves that will reverse the water flow from one end of the membrane to the other. This will essentially rinse the membrane...I have a timer LCD that can be set to reverse water flow about every 5 days or so. I believe a normal rinse cycle (not backwash) just closes the permeate line and allow full flow thru the membrane in the opposite direction for say maybe 10 min. My question is: since the membrane is equipped with a lip o-ring seal on the entering water end (so you don't bypass water around the membrane to drain, but lets all the water pass thru the membrane) should I install another lip seal on the opposite end so when the membrane is operating in reverse, no water will bypass?
Mark Timmons
June 23, 2017 at 10:54 AM
The reverse flow flush isn’t a recommend design. It is best to have a permeate flush after each process. This would be an optimal flush and much less complicated. By adding a brine seal, you can create pressure between the vessels that might be damage the membrane. I have been doing this for 45 years and over the years, I have seen 40 or 50 people try and build their own RO system. If yours works, you will be the first. It's a very bad idea. RO will not remove sulfur, but rather, it will concentrate it and it will likely not remove the tannin.
Mark Whitnell
June 23, 2017 at 9:00 PM
It's a shame you are only a 45yr inexperienced 'wanabee', not an engineer. You have only negative responses to comments that don't reflect what you believe. I expected a comment such as this. If you had any thing positive to say, it would have to be in line with what you 'think' is best based on little engineering expertise. Adding a brine seal to each end would never compromise a pressure differential between the brine side and the permeate you really know about fluid flow? I guess you can't put PE along with your name...
Mark Timmons
June 24, 2017 at 2:45 PM
You are one of those guys who think they know it all. I don't think I know it all so I ran this past 3 other engineers who have a combined 114 years of reverse osmosis engineering experience. That was their answer as well, but you are evidently smarter than us all, so you resort to name calling like a teenager. Insults are the last resort of insecure people trying to appear confident in their weak position. Remember what I told you. I stand by it.
Allen Farnsworth
January 5, 2018 at 3:46 PM
If “insults are the last resort of insecure people trying to appear confident in their weak position” then you must be one of them for making that statement. Sounds to me like saying you are not a fluids engineer is spot on since you didn’t try to refute that. I would also guess that the 3 engineers you refer to all work for the same company and have a vested interest in backing you up.
Mark Timmons
January 7, 2018 at 10:53 AM
I was not the one who resorted to insults. I simply responded when someone did. It doesn't really matter, but the 3 engineers I spoke to all work for different companies. No, I am not a fluids engineer - you evidently are, so I will write slowly to aid comprehension. Sometimes common sense (which is not always common) and experience are more important than an engineering degree.
February 18, 2018 at 7:16 PM
Hello my name is Scott and would like to know if you do have Reverse Osmosis system for sale and if you do kindly email me with the sizes and types that you have including with their prices range on them thank you . Thank you Scott.
Mark Timmons
February 18, 2018 at 7:26 PM
Yes we do. Here they are:
Ralph mongelli
January 24, 2019 at 9:16 PM
can the osmosis system be clean out? my unit has been out of service since 1999. i was told to use an new one becuse the tank may have bacrteria.
Mark Timmons
January 25, 2019 at 9:13 AM
I recommend replacing the RO tank every 5 years. If it has been out of service since 1999, it must be older than that. This is your drinking water I am talking about. I'd rather drink out of a pond that a system that old. Back then, it probably was not lead-free either. I don't know about you, but I can't afford to loose anymore brain cells from damage caused by lead exposure. I agree that you should buy a new one.
April 21, 2019 at 1:06 PM
Twice our reverse osmosis water has made us very sick. We changed the filters when needed as the system would stop making water when needing to be changed. We were never told we had to or told how to sanitize the system with bleach. The second time we got sick the air gap device had a black slimy moldy looking build up on it. The water co came out and replaced the air gap and "sanitized" the system with some bleach. The guy said he didn't know what caused it or what was making us sick. I no longer trust using the system, it was a huge waste of money. I have no way of knowing if bacteria or mold is still in the system. I hate city water but after this experience I've decided its probably safer.
Mark Timmons
April 24, 2019 at 10:31 AM
Terri, 1. You should not sanitize your RO with bleach; 2. Did you do a bacteria test and determine that there were bacteria in the RO system, or did you just get sick after changing the filters and felt it was easy to blame it on the RO filter change? 3. It would be normal to see some black airborne bacteria on the air gap. That is the drain water, not the drinking water, and I just want to be sure you are not drinking out of that. 4. It is common, that heterotrophic bacteria (non-pathogenic) can build up in an RO tank. That is why we offer this: It kills the bacteria right before it comes out of the faucet. 5. I fail to comprehend how water that is untreated and may contain a chemical cocktail of over 38,000 different chemicals can make you think it is safer. The bacteria filter solves the problem. Taking out the RO system is like throwing the baby out with the bathwater.
April 24, 2019 at 10:31 AM
Sounds like fear mongering with “may contain 38,000 chemicals” Do you have any citation to back that statement up? If the source of water is fouled with pathogenic microbes, switching to a municipal water supply which is treated with chloramine or other sterile ya may be safer for you than drinking water fouled with microbes. If this person did have a Compromised RO system, it could be concentrating the microbes while removing ions from the water.
Mark Timmons
March 15, 2020 at 12:31 PM says this: "Under the amended TSCA, manufacturers were required to report to EPA chemical used in commerce from June 2006 through June 2016. The latest draft of the inventory listed 38,304 chemicals, representing many chemicals that are not used in commerce today or are only being produced in very small amounts." I am not sure what else you are trying to say.
August 9, 2019 at 1:44 PM
Hello Mark Timmons What tests can we perform on water to determine if it is infected with certain types of bacteria? What bacteria would it test for? Is a water distiller safer in terms of killing bacteria versus an RO system? Thank you
Mark Timmons
August 9, 2019 at 3:57 PM
This is the best test: It tests for coliform which is the best baseline.
March 22, 2020 at 12:04 PM
So we install this after the RO tank and immediately before the faucet? Wouldn't bacteria continue to grow in the RO tank then? Thanks.
Mark Timmons
March 27, 2020 at 1:37 PM
Yes, because even if you put it before the tank, bacteria will appear. I recommend replacing an RO tank about every 5 years anyway. I guess you could install two. ;)