Pool Chlorine: What It Is, How It Works & What Are The Alternatives?
Most drinking water supplies and 99% of the world’s swimming pools use chlorine for sensitisation, while the vast majority of Hot Tubs use the similar but more expensive bromine, due to its resistance to high temperature. Why chlorine for pools? For two major reasons:- it works in seconds while still at low concentration, and it persists reasonably well in the water, penetrating pipes and distant corners of the pool if there is reasonable circulation. However, effective/optimal chlorine use is difficult in pools as it requires precise control of pH and needs to be supported by several other chemical in pool use. Is there a better way?
What is Pool Chlorine?
Chlorine is a chemical element on the periodic table (part of the halogen group) that is commonly used as a sanitiser in swimming pools due thanks its ability to deactivate and destroy multiple types of bacteria and viruses. Pool chlorine operates effectively in water that has a pH between 7.2 and 7.6 and is commonly available in liquid, granular or tablet form.
How does Pool Chlorine work?
Conventional pool chemistry is complicated and difficult to manage well. Tight limits on pH, pool chlorine, buffer, calcium, chemical stabiliser levels (and more) mean there’s only a narrow window for it to operate efficiently within and this makes it difficult to maintain the small ‘sweet spot’ where everything works harmoniously.
Chlorine, as used in over 99% of pools, is a poor disinfectant in water with a pH greater than 7.6. This is a problem because most pools drift continuously to their natural pH of around 8 – 8.5. pH must therefore be controlled through the constant addition of acid and buffer to ‘re-activate’ the chlorine and keep the pool correctly sanitised. Chlorine also breaks down quickly under sunlight. Stabilisers are used to counteract this effect and maintain disinfection through the day.
Other problems arise when organic matter from swimmers (and surrounding areas) get into the pool and form noxious and irritating chloramines. These are what’s responsible for sore eyes and strong chlorine smells.
So with pool chemistry being affected by temperature, the pool surface, rain, the amount of sunlight (and shade) and bather activity it makes conventional pools very difficult to manage… manually. Effective pool chemistry control (with conventional pool chlorine) really requires automation based on chemical sensors, chemical dosing pumps plus additional, manual chemical addition based on test kit readings. It also requires handling and storage of large quantities of dangerous chemicals.
What’s the alternative to pool chlorine?
Pooled Energy’s Advanced Water Chemistry system operates at the natural, equilibrium pH of the pool and subsequently, in most cases, requires little or no acid addition. It works so well because it has a larger operating ‘sweet spot’ of 7 – 8.8 pH where the pool sanitiser is still effective and the water is comfortable.
For sanitation, Pooled Energy uses a combination of chlorine (generated by a conventional salt water chlorinator) plus bromine as an enhancer. Bromine is a premium sanitiser, that’s commonly used in spas but, unlike chlorine, is effective in higher pH environments. Bromine is also more stable at higher temperatures (which is why it is so common in spas and hot-tubs) and it doesn’t form irritating chloramines.
Instead of algaecide, Pooled Energy uses a zinc as a natural phosphate starver to inhibit the growth of algae. Plus, it uses magnesium salts to soften the water and protect the chlorinator and pool surfaces from calcium deposits.
Overall, Pooled Energy’s Advanced Water Chemistry needs very low amounts of chlorine and other chemicals added to the water when compared with conventional chemistry. This results in less irritating, more pleasant, better sanitised water that’s much easier to manage.