Swimming Pool Blog
by Rob Cox, February 22, 2017
Alternative Pool Sanitizers 2017
The term 'Alternative Pool Sanitizers' has been around a long time, and usually refers to alternatives to chlorine. Over the years I've seen dozens of new developments in pool water sanitation. Some were here today, and gone tomorrow, and others have stood the test of time, and have become popular products for pool owners.
Since we haven't touched this topic in several years, it's ripe for an update. Today's post explores alternate methods of pool water treatment, those that reduce reliance on chlorine, or eliminate it completely. I'll include those that have stood the test of time (20+ years), plus a couple of new treatments you may not have heard of yet.
Not really an alternative pool sanitizer, think of salt systems as alternative chlorine delivery systems. In the 80's inventors added salt to the pool in the right amount, turned on the electrolytic salt cell, and changed slightly salty pool water into chlorine. You may still have to keep some chlorine tablets or at least pool shock on hand, because you can't create chlorine if you have pump, filter, or salt cell or control problems, and you still may need to shock the pool (although you can use non-chlorine shock if you want). With a salt system installed however, you can go months without having to use any packaged chlorine products. It's still a chlorine pool, but pool salt systems are known for less chlorine smell, and the water is 'silky smooth', with the addition of the pool salt.
Copper and Silver ions are excellent bactericides, a fact that has been known for thousands of years, since the first copper bowls and water pitchers became fashionable. Also in the 80's, Fountainhead Technology introduced Nature 2 Mineral Purifiers which has become a popular way to reduce chlorine demand by 50%, while adding a shine and sparkle to the water, zapping very small particles to improve water clarity. King Technologies also has the Frog Mineral System, also with 6 month mineral cartridges, and the chlorine Bac-Pac cartridges, for a complete sanitation system. In addition to 'erosion' mineral feeders like Nature 2, a Power Ionizer is also available that uses energized copper or silver plates, to introduce an adjustable amount of metal ions into the water.
Another kid from the 80's, Del Ozone produced the first UL listed ozone system for pools, in 1984. They have continued to lead the market in ozone technology for pools and spas, with very little competition. Pool Ozonators work by creating an O3 molecule. Soon after creation (by UV bulb, Corona Discharge or Plasma Gap methods), the O3 gas is pumped into the pool plumbing line where it zaps everything it comes in contact with during a short trip in the pipe and pool, before it rising to the pool surface. Ozone is one of the most powerful sanitizers known, however, it's hard to get that microscopic ozone gas to contact every cubic cm of your pool water. Like minerals, ozone is not usually used as a stand alone sanitizer, but can reduce chlorine consumption by 50-80%.
UV LIGHT SYSTEMS
A more recent alternative pool sanitizer, but also one that has been known for thousands of years - sunlight kills bacteria. In fact, on a sunny day the top 6" of pool water is more sanitary than deep water, from UV rays. Ultra-Violet lamps that produce UVC rays in the germicidal spectrum of 254 nm have been developed for pool water sanitation in the last 10 years. UV systems for pools work by passing your pool water through a chamber where it is bathed in the eerie blue light of UV rays, which zaps bacteria and other germs. Like salt, ozone and mineral systems, a UV pool system is also plumbed into the return pipe, and powered by plugging into a GFCI outlet. Solaxx has been a leader in UV systems for pools, but the big boys are taking notice, with Pentair and Hayward producing UV systems.
The new kid on the block, Hydroxy Radicals are a whole new disinfectant, a third sanitizer produced by combining UV and Ozone. It's known as AOP, or Advanced Oxidation Process, that creates hydroxyl radicals (OH-) when ozonated water is irradiated with UV-C rays of a specific wavelength. The hydroxide OH- behaves in a manner similar to hydrogen peroxide, and is thus a powerful disinfectant. AOP produces a short-term residual, and builds a hydroxide bank that continues to sanitize. In the last few years, several new pool AOP systems have become available in Hayward's UVO3 system, Clear Comfort CCW100, and Del Ozone's Solar Eclipse. With proper sizing, accompanied with optimum filtration and water balance, AOP systems can be used as a standalone sanitation system.
Not a new sanitizer, Biguanides are polymers that behave as disinfectants and antiseptics. They have widespread use in hospitals, and in the late 70's, was patented as an alternative sanitizer for pools and spas. Biguanides combine the PHMB with a hydrogen peroxide shock, and have other accessory chemicals available, as a complete sanitizer system. They are expressly non-chlorine, and very incompatible with chlorine and bromine products of any type. Users enjoy no chlorine smell, reduced testing and treatment, and a completely chlorine free pool, when combined with optimum filtration and water balance. Baquacil is the original brand, along with newer competitors Aqua Silk and Soft Swim.
>>>So there you have it, 5 alternative pool sanitizers that have stood the test of time, and one new kid on the block. With the exception to Biguanides, which can't be mixed with chlorine, most of these sanitation systems still need a little bit of chlorine to work best, and for peace of mind in knowing the water is truly sanitary. Used in this manner, I like to call them 'supplemental sanitizers'.
If you really want to go truly chlorine-free, I would suggest first installing a big DE filter and a variable speed pump, and then install an AOP system, or go with Minerals + Ozone and/or UV, and a little non-chlorine shock once per month.