We have all walked into a swimming pool facility, health club, or small motel and immediately recognized that “chlorine” smell emanating from the pool. We have grown to accept the odor and the other side effects of chlorine disinfection as the price paid to have a sanitary swimming pool. The odor and many of these side effects are not actually caused by the chlorine, but are the by-products of chlorine disinfection. Chlorine and bromine are common aquatic system disinfectants and are very effective at killing bacteria. They, and their halogen brothers fluorine and iodine, are all effective sanitizers because they are strong oxidizers (oxidation is the way bacteria is killed). Halogens, like chlorine, are all one electron short of filling their outer electron shell. They are always looking for another compound from which to steal an electron (oxidize). However, their oxidative power is not limited to just attacking bacteria.
Disinfection by-products (DBP) are formed when chlorine oxidizes organic compounds. These organic compounds are found in bacteria and many are critical for the bacteria to live and thrive. However, a lot of organic compounds are naturally present in our water, and putting people into the water introduces even more of these materials (dead skin cells, sweat, urine, etc). When chlorine interacts and oxidizes these organic compounds, it results in a tremendous amount of newly created compounds…but, these now contain chlorine (DBP). We generally classify some of these as combined chlorine or chloramines. It has now been established that many of these DBP are toxic, and while most remain in the water, some are quite volatile and released from the water into the air (i.e. chloroform). These DBP are what we recognize as that “chlorine” smell.
In short, chlorine is going to cause a reaction with anything in its path, and some of these reactions are going be toxic. So, that funky “pool smell” isn’t the chlorine. It’s the dark side of chlorine’s work.
Research at Embro Corporation (Creative Water Solutions’ sister company) is actively investigating the process by which DBP are formed, and the levels of DBP in swimming pools and spas. Our early results have demonstrated that Sphagnum moss leads to a reduction in DBP levels within the first few months of use in a swimming pool. Pointing to the importance of this research are the increasing numbers of scientific articles documenting production of toxic DBP in aquatic systems. They illustrate increased health problems for those experiencing high exposure to these compounds, including competitive and avid recreational swimmers. Stay tuned to our newsletter and website for the newest results of our research in this area.
Now that you’ve flushed your spa once, twice or as many times as it takes to get it all out, how can you prevent organic contamination from forming again?
Remember – organic contamination forms when bacteria in solution adhere to a surface, divide and cover themselves with a protective layer of slime (mucopolysaccaride). Learn more at Montana State University’s CBE site.
You could try to completely sterilize your spa and the spa water and keep it sterile; drain the spa and use fresh water every week; use a flush to remove all organic contamination once or twice a month and replace the water; OR you can prevent formation of organic contamination while killing all swimming bacteria. Let’s look at each one.
The Hard Way:
Sterilize your spa and water
There is no easy way to sterilize every surface in your spa short of sending it to an industrial sterilization facility that uses high power x- rays. Even if that was done, the water placed into the spa would have to be sterilized, and you couldn’t use the spa because the second you stepped into the spa the bacteria on your skin would quickly repopulate the spa water and the spa surface. In my research laboratory, we conduct many experiments under sterile conditions and keep the systems sterile. The amount of work and equipment in addition to training required to accomplish that is enormous.
Drain the spa and use fresh water every week
This is essentially how commercial spa operators try to keep their spas within health department guidelines. They often use a measurement called “total dissolved solids” to determine when to dump the water and start fresh. Depending on the bather load, this could be done twice a week or weekly. The water is then treated with a sanitizer like chlorine to keep the bacteria count in the water within safe limits. This approach uses a lot of water, takes a lot of time, and does nothing to address the formation of organic contamination in the spa. With the organic contamination present in the spa, any excess bacterial challenge or change in bather load will “tip the balance” of the water and require more frequent water changes.
Use a flush to remove all organic contamination once or twice a month and replace the water
As we discussed in my last blog (September 23, 2009), we now have an effective flush system that efficiently remove organic contamination from surfaces and keeps it in solution. When the spa is drained, the organic contamination goes out with the water. With fresh water and sanitizer in the spa, new organic contamination will form over time requiring reflushing and fresh water. Theoretically, the water should last longer between changes than the previous scenario, but with frequent spa use, flushing would have to be done once or twice a month. The same problems as above make this treatment plan a real problem.
The Easy Way:
Prevent the formation of biofilm and control the number of swimming bacteria
This solution is ideal. Up until the discovery that certain species of moss prevent the formation of organic contamination, this was a just a theoretical possibility. We know that sanitizers like chlorine and bromine are very effective killers of bacteria that swim. We now know that these same sanitizers are absorbed by organic contamination and fail to kill all the bacteria within the organic contamination.
Here’s how we now think this works: Combining the moss with sanitizer solves the problem. The moss prevents organic contamination from forming, allowing the sanitizers to efficiently do their work on planktonic (swimming) bacteria. The moss also inhibits bacteria from dividing, so there are fewer swimming bacteria to kill. Combined with the moss’s ability to remove heavy metals from water and stabilize pH, the spa water becomes stable, clean, clear and safe. See the video on our website for more information
My name is Allan Schwartz and I have been working in the pool and spa industry for the past five plus years. The majority of this time has been spent focused on the residential part of this channel with Creative Water Solutions.Watch movie online The Transporter Refueled (2015)
Eau de Chlorine?
Late this April, I was out to dinner with some close friends, Michael and Suzie S. We were talking about working out at the Minneapolis Jewish Community Center where both of our families belong.
“Chlorine is my perfume” – this isn’t how it has to be for swimmers!
Michael was talking about how much he enjoys swimming now that he can’t run anymore because of his failing knees. He goes multiple times per week. Suzie stated at that point that she can always tell the days he has been swimming because in spite of showering after his swim, he still smells like chlorine and she doesn’t like to be around him.
Michael then asked me “why don’t you talk to the JCC about using your PoolNaturally® system for their pools”. Michael reminded me about the positive feedback I have been telling him about from our residential pool and spa customers. As it turns out, my company had been talking about beginning to expand into the commercial pool and spa segment of this industry.
A Natural Partnership
The JCC was very interested and were an excellent candidate because they have six different types of water bodies. They have a men’s and women’s spa, an indoor and outdoor wading pool, as well as large indoor and outdoor pools. The JCC started in May with their men’s spa which was the most troublesome area. Then the outdoor wading and swimming pools were added. Almost immediately, the bathers were approaching the lifeguards to inquire about what they were doing differently with the water. The changes were dramatic. Becky, the lifeguard supervisor recently commented on how much more enjoyable the pool water is considering how much of their working day is spent in the water.
Jon S, the Certified Pool Operator and maintenance supervisor, told me that while he was originally very excited to try our PoolNaturally® and SpaNaturally® systems. If he hadn’t been so involved with the changes he wouldn’t have believed them. The results have exceeded his expectations. Ironically, because of mechanical issues with the indoor lap pool, it will be the last pool to go on our PoolNaturally system. Michael S, who suggested the whole idea, swims in the indoor pool and has been anxiously waiting to swim and not smell like he is using chlorine as an after shave.