Chlorine Alternatives For Efficient Swimming Pools

Cannonball! Jumping into a swimming pool is a classic way to beat the heat on a hot summer day. But clean pool water requires a combination of filtration, circulation, and sanitization. Chlorine has long been the most common tool for keeping pools free of bacteria and algae – but it has its drawbacks, and there are alternatives.

An efficient alternative pool sanitizing system can minimize the expense, time, and effort of chlorination, as well as its nasty side effects. You can make your pool healthier, you can reduce your environmental footprint (both from spillage of chlorinated water and using unnecessary amounts of chemical additives), you can save money, and you can help preserve your pool liner and pump system with some of the following pool sanitizing systems.

Why Not Chlorine?

Chlorine is actually a very effective sanitizer for applications like pools. But many swimmers don’t like the smell and feel of chlorine, or its bleaching effect on hair and clothing. Over time, it can also cause corrosion and damage to pool liners and equipment like pumps, resulting in expensive repairs. Pool owners must constantly add quantities of chemicals to the water, and the expense adds up.

Possible health effects of concentrated chlorine are another drawback. When chlorine combines with organic material (like sweat, hair, and all the other things that swimmers can introduce into pool water) it produces compounds like chloramines and nitrogen trichloride – which have been linked to a host of health problems, including lung disorders like asthma.

It’s worth noting that most alternatives for maintaining pool water still require a small amount of chlorine for residual sanitizing. A system that pumps water through a purifier for its primary cleaning must still be able to quickly eliminate any pathogens introduced into the main body of pool water, and areas like pool walls need to be kept free of algae. But the required amount and concentration of chlorine can be drastically reduced.

There isn’t a single “best” system for every pool, but here is a look at some alternatives to traditional chlorine systems for keeping swimming pools clean and clear.

Ozone Pool Systems
Ozone is a powerful oxidizer, which means it can be a very effective water sanitizer when circulated through a pool. Most pool systems utilize either an ultraviolet light source or a corona discharge tube to convert ambient oxygen in the air (O-2) to ozone (O-3), which is then injected into the jet system of the pool.

Ozone dissolved in a pool’s water oxidizes impurities, and it also helps encourage oils and particulates in the water to clump together so they can be filtered more easily (be sure to step up your filter maintenance accordingly to avoid clogs). Ozone won’t directly alter the acidity of pool water, so users may find it easier to balance the pH levels. And ozone systems can easily be retrofitted to treat the water in existing pools.

Water circulation is important in this type of system to ensure distribution of the ozonated water. Ozonated water must still be treated with a “backup” sanitizer like chlorine to quickly neutralize any pathogens introduced by swimmers, but only about 20% as much chlorine is needed compared to a traditional pool. Also, water typically remains clearer for a longer period of time with ozonation than with chlorine systems.

Ultraviolet Light (UV) Pool Systems
A UV pool treatment system uses an ultraviolet light source to kill pathogens as the water circulates through the sanitizer unit (which shouldn’t be confused with the UV lights that can be used to produce ozone).

Ultraviolet light does a good job of eliminating pathogens in the water that flows through the disinfection point, but since there is no residual sanitization throughout the rest of the pool, and since these systems won’t maintain water clarity on their own, a supplemental treatment like chlorine must be used. But similar to ozone systems, UV systems let users substantially cut the amount of chlorine required, reducing usage by up to 70%.

Another advantage: in addition to killing bacteria and viruses, ultraviolet light can also be very effective for eliminating protozoa such as cryptosporidium, which chlorine alone can be very slow to eliminate.

Metal Ion Pool Systems
A number of “metal ion” systems have emerged on the market in the last few years that utilize metallic bars (such as silver and copper) for ionization to treat pool water. While this approach can help prevent the growth of algae and reduce bacteria, these systems alone are generally not able to kill pathogens quickly or thoroughly enough to be used without supplemental chemicals like chlorine – even though some are marketed as “chemical-free” systems. In addition, these systems may require water pH to be maintained at very low levels, which can void warranties on equipment like pool heaters.

The Australian government recently spoke out about the importance of swimming pool sanitizing systems, and voiced concerns about silver- and copper-based ion systems being used without supplemental chemicals. You can read the article here to learn more about this issue, and the general need for proper pool water treatment.

Natural Aquatic Plant Pools

“Natural” swimming pools have gained popularity in Europe, and homeowners in the US are starting to take notice. These pools essentially recreate the ecology of a pond in a controlled setting, where plants, beneficial bacteria in the water, and sometimes even fish provide all the necessary filtration and cleaning. A properly designed system will offer crystal-clear water that’s free of chemicals like chlorine

Natural pools are usually purpose-built, since converting an existing pool is a complicated process. And they’re not cheap (typically 10-20% more expensive than traditional custom in-ground pools). But these pools can be visually stunning, and blend beautifully into the surrounding property.

Proponents of natural pools contend that they are the “greenest” option available. They point out that natural pools require no toxic chemicals, add vegetation to the landscape, and can even help support local wildlife.

Woodhouse Natural Pools is a UK-based firm that specializes in natural pool design and construction. Learn more at the Woodhouse website.

So where does this leave you, the pool owner? If you want to move away from a traditional chlorine-only system in your pool:

Do your research. No one system is the “best” for every user. And remember that sometimes the “experts” have their own interests in mind. A salesman might neglect to mention the drawbacks of one system, or unfairly discourage users from another system simply because it’s unfamiliar.

Don’t change just for the sake of change. Maintaining a safe and healthy pool is your first priority. An alternative system that seems innovative or user-friendly is useless if you aren’t sure it also properly treats the water you’re swimming in.

Know your needs. Do you occasionally swim solo in a small lap pool, or do you frequently host huge pool parties in a mini-ocean? Also, be realistic about how much work you’re willing to do. Some owners love to learn about the equipment and tinker with the setup, while others want a self-contained system that they never need to think about.

Consider your existing setup. If you’re outfitting a new pool, you can start (literally) from the ground up. If you’re retrofitting an existing system, make sure any new system is compatible with existing equipment like pumps and filters, and find out if performance or warranties will be affected.

Have you tried any of these alternative pool treatment systems? Leave a comment below and let us know!

If you enjoyed this article, get email updates (it's free):

Email Address:

Tagged as: chlorine, chlorine alternatives, nasty side effects, nitrogen trichloride, pool sanitizer, possible health effects, Sanitizer, Swimming, water, width