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Do Pools Need Chlorine?

do pools need chlorine?
Do pools need chlorine? In a word, yes. An inescapable reality in the pool and spa industry is that consumer attitudes towards chlorine as a chemical sanitizer in water are at an all time low. More than ever people are exploring alternatives to chlorine and asking about ways in which they can make their pool chlorine free. To start off you should read this article about pools without chlorine to learn some of the risks and reasons behind trying to run your pool without a chemical sanitizer.


Most pool owners have not actually done the research themselves. Most have just heard that chlorine is bad, because "chemicals are bad", and so they start looking for a way to operate the pool without chlorine (or other chemical sanitizers like bromine). The big problem here is that in one giant step the pool owner has undermined every known convention about water quality and how to keep bodies of water safe to be in or around. This is a very bold step to take - too bold really.


In an attempt to seek a healthier alternative to something that is possibly not good for you, you for sure exposure yourself to some serious risks. The health risks of chlorine are something that we can definitely have a conversation about...but the health risks of non chlorinated water are not a topic up for debate.


Dirty water is the most dangerous thing on the planet - The World Health Organization states that 3.4 million people die every year from dirty or contaminated water, which makes this the single largest cause for human death annually. Period. You might think - Yeah, but a lot of those deaths are in places like third world countries, Africa, Asia, all over the place. This is true...and do you know what is the main difference between those places and the place where you live is? Chlorine in our water. Mic drop.





I am 100% in support of pool owners who want to pursue having the healthiest, safest possible swimming pool and water quality. I am not in support of people who attempt to skirt the best line of defense we have, ignorant of the incredibly serious nature of the risk they are exposing themselves to. For another opinion on this important issue I asked Rudy Stankowitz, President of Aquatic Facility Training & Consultants, LLC. Rudy travels the world teaching water quality and management techniques with the goal of protecting swimmers by reducing hazards at aquatic facilities through education. He had this to say on the subject of pool owners wanting to go "chlorine free".


Rudy Stankowitz
In an industry hungry for an alternative to chlorine, perhaps we should remember the zoonoses that prompted its use in water treatment in the first place. It is true that use of the halogen can lead to the formation of harmful byproducts, but right now, it is the best we got; understand that there is no such thing as a zero sum game. Still when we investigate products such as Ozone and UV, it is important to understand that neither is a stand-alone system, both requiring a minimal residual of disinfectant. The "Natural Pools" looming in the beginning stages of a North American European invasion muster thoughts of Elly May's "cee-ment pond", while simultaneously conjuring fears of cholera and other waterborne illnesses we had used chlorine to prevent. Many folks make a good living preventing swimming pools from having this au naturale look that seems to accompany the lily pad clad chlorine free oasis. Maybe the answer is not in an alternative to chlorine, but in consumer-based chlorine education, using the product correctly versus abandonment, adding the correct doses and only when needed. Alternatively, what if instead of chlorine, we could have better chlorine? The use of chlorine dioxide (ClO2) is becoming popular in swimming pool treatment overseas and its usage in water treatment has grown substantially over the last twenty years (>15% of water treatment facilities in the U.S. are now using chlorine dioxide). The appeal of chlorine dioxide lay in the fact that it is a much more powerful disinfectant that produces a significantly lower level of DPBs compared to traditional chlorine when used correctly. There is much documented success of the product in the treatment biofilm. More testing is required before they pull the trigger and release this brand new (developed in 1804) sanitizer on the North American market, but maybe ClO2 will be the "chlorine of the future".

Rudy Stankowitz, CEO of Aquatic Facility Training & Consultants, LLC



safest way to reduce chemical exposure is learning to work with chlorine
Wow, that was a mouthful. For the uninitiated, there is so much knowledge dripping out of that text block I am worried that most pool owners will miss the important details of what Rudy is saying here. First, zoonoses are diseases that can be passed from animals to people. Next, what Rudy is saying with about water quality not being a "zero sum game" is that there is no perfect system currently that will make the water 100% safe without having at least some potential risks or downsides.


Next, and easily the most important thing that Rudy touched on, at least in my opinion, is that most likely the best solution, at least right now, involves more correct use of chlorine, versus abandonment of the chemical entirely. Further to this he goes on to give an example of how chlorine is already being used differently in some areas with greater success. But what the average pool owner does not read in this comment, and yet it is something that both Rudy and I (and every other pool technician) knows, and that is that most pool owners are not using chlorine properly, and do not have a complete understanding of how chlorine works and the limitations of chlorine.


Rudy is correct that there likely will be a "chlorine of the future" one day, but if you are a pool owner here reading this article today then you do not so much care about where the industry will be in 25 years like Rudy and I do. You want a solution to chemicals in your pool right now...and Rudy gave that to you. You need to learn how to manage your chlorine better. This is not a "dig" on uninformed pool owners...this is a real problem and he knows it only too well. Most people could very well be exposing themselves to less chlorine than they are in their pool simply by understanding the chemical process of water management better. To help you understand this better consider some of these examples:


Cyanuric acid and chlorine levels - CYA, cyanuric acid, water conditioner and pool stabilizer are all the same thing. This is your "sunscreen for chlorine" that you need for any pool that gets direct sunlight. Without any stabilizer in the water it would be impossible to maintain residual chlorine levels as they would degrade in the UV light every day. However, on the other end of the spectrum, when your CYA levels climb up above 50ppm, and especially over 80 to 100ppm, chlorine is vastly less capable at sanitizing the water. This means you need more chlorine, and the stuff you do have is not protecting you as well as it should...maybe not protecting you at all. Mismanagement of the CYA in your pool, in either direction, could expose you to greater levels of chlorine than needed, plus an increased risk for the water not being protected. Understanding the importance of CYA, and keeping it in the right range are both ways to reduce risk as well as reduce your overall chlorine exposure.


Chloramines and total chlorine - Your pool water doesn't have chlorine. Your pool water has free chlorine, total chlorine and combined chlorine (chloramines) as well. The less you know about this the less you will be able to minimize your chemical use. As chlorine works in your pool you will develop some "used up" chlorine in the form of chloramines. If you do not do anything about it these chloramines can add up and begin to cause problems with your water such as a bad smell, chlorine smell, red eyes or itchy skin. If you have a difference between your free chlorine level and your total chlorine level of 1 part per million, or more, then this indicates a significant accumulation of combine chlorine (chloramines) which needs to be resolved. There are a few ways to remove chloramines, such as breakpoint chlorination which involves shocking the pool to much higher levels of free chlorine for a sustained period of time, but you can also use peripheral equipment like an ozone system to help limit combined chlorine in the water. You can also use an oxidizer chemical instead of a peripheral ozone system injecting o3 into to the water with similar effectiveness. Which method you use to limit chloramines in your water is a subject for another article, but for this purpose you can be certain that minimizing your chlorine exposure will involve eliminating chloramines in your pool water and keeping your combined chlorine level as near to zero as possible.


Chlorine lock - In the first example when CYA is too high the chlorine can not work properly in the water. This is a form of "chlorine lock" as technically there is chlorine...it just can't work for some reason. Well, another one of the reasons that chlorine might become locked, or ineffective despite having a measurable reading, is when your pH is not where it should be. Most specifically, instances where you have a high pH, especially at or above 8.0, the effectiveness of the chlorine is severely limited. This can cause situations like green water, which could result in you needing to increase your chlorine levels even further to combat this. Part of effective chlorine management in a swimming pool is the balance of pH and total alkalinity. It is not simply enough to use chlorine in your water, you need to learn how to manage the pH to keep the acidity of the water in the correct range.


Regular oxidation - If you are not using an oxidizer chemical, or don't have a piece of peripheral equipment like ozone installed, then you are almost certainly using more chlorine than you could be using. The only question is whether you consider oxidizer chemicals or other byproduct chemicals from ozone or UV to be any better for you than chlorine. If you are looking to avoid all chemicals...well...technically the air you breathe is all chemicals. And so is water. So you really must begin to differentiate between good chemicals and chemicals you want to avoid. If you want to get the most mileage out of the chlorine that you add to your pool, then the bottom line is that oxidation will help you to achieve this goal.


salt water is not safer than chlorine
These are just a few examples of the ways in which you can mismanage your chlorine and end up using more than you need, using additional chemicals unnecessarily, or exposing yourself to risk inadvertently. Education is pivotal in learning how to balance your pool and spa water safely. When used to the best possible potential, chlorine might not be a perfect zero-sum game, but as Rudy said, "It's the best we got". So often pool owners will switch to salt water thinking it is an alternative to chlorine, which it is not, and then end up running their pool with a pH of 8.2+ and use far more chlorine than needed since the pool keeps turning green. In the industry we see this every day and it is frustrating to say the least. With good water management fundamentals you can seriously minimize your exposure to chlorine while maximizing the protection that you are getting from what you do have in the water.


Instead of looking to replace chlorine or find a chlorine alternative, you should look to adopt peripheral equipment that reduces chloramines, such as an ozone system, or possibly an AOP system. This will oxidize bacteria and organic debris directly as well as reduce the combined chlorine in the water. Use this in conjunction with well maintained CYA levels and a pH of 7.4 to 7.5 (total tolerance range) and you can be reasonably confident that you are minimizing your risk, minimizing your chemical exposure, and maximizing your overall swimming experience. If you genuinely want to limit your chemical and chlorine exposure then every ounce of energy you would put into finding a different solution would be much better spent learning how to properly and efficiently use the best system that we currently have in place to protect swimming pool water - chlorine.


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