Pool Water Treatment

The outcome of an ideal water treatment system for a pool, spa, or swim spa is to give you consistently clear water, and a method that is easy to use.

There are a range of water treatment options available to you as a pool owner. Below we have summarized the most popular of these, along with their advantages and disadvantages.

Pool and spa water treatment options

Smaller pools (such as our fiberglass swim in place pools) hold less water, are easier and less costly to maintain, and use fewer chemicals compared to full-sized swimming pools.

Also, a smaller current pool with advanced paddlewheel technology can provide you with all the benefits of a large pool.

Ultimately, the pool water treatment system that is the right choice for you will depend on your budget and the time you want to spend on maintenance.

We recommend ozone or UV pool systems. In our experience, these pool sanitation methods have distinct advantages over others.

Find out how a SwimEx 500 OS swim spa owner has eliminated the need for chlorine or bromine in his pool.

UV pool systems


  • UV purification systems take water purification to the next level. Water is passed through ultraviolet light to kill harmful organisms.
  • UV destroys bacteria and other harmful particles with no chemical side effects. It is a safe solution that removes all if not most of the dangerous microorganisms from your water.
  • UV is environmentally friendly. It emits no by-products.
  • UV requires little maintenance. Most UV systems require only an annual bulb change.
  • There is no chemical smell or taste.
  • UV is a supplemental oxidizer and disinfectant. It must be used with chlorine as it is not a residual disinfectant, but it will significantly reduce the amount of chlorine or bromine needed.


  • To be effective, pool water must be relatively clear to start with. If the water is cloudy, it will hinder the ability of the UV light to penetrate the water and destroy microorganisms. Any microorganisms the UV treatment misses remain in the water. A small amount of chlorine will still need to be added.

Pool ozone

Ozone is oxygen (O2) with an extra oxygen atom attached (O3). The third oxygen atom oxidizes and destroys microorganisms in your pool, including bacteria, viruses and parasites. Ozone further breaks down and destroys contaminants such as cosmetics, body oil, and perspiration found in the water.


  • Much like UV light, ozone produces fewer by-products than chlorine.
  • Ozone does not cause the treated water to have an unpleasant odor.
  • Ozone destroys microorganisms in your pool, including bacteria, viruses and molds.
  • Easy to install, simple to maintain.
  • Little maintenance.
  • Environmentally friendly.
  • Ozone is a supplemental oxidizer and disinfectant. It must be used with chlorine as it is not a residual disinfectant, but it will significantly reduce the amount of chlorine needed.


  • Ozone is more expensive up front. The ozone generator will need to be replaced periodically.

Chlorine water treatment


  • The most commonly used pool sanitizer, chlorine. It is very easy to find. It comes in several forms: tablets, liquid, and granular.
  • Chlorine effectively kills or inactivates pathogens and algae. It also oxidizes or chemically destroys other materials from the environment or users.
  • Chlorine acts as a residual sanitizer, which means it can remain in the pool long after it is applied.
  • Chlorine can also be stored for long periods of time.


  • If not maintained properly, chlorine can cause red eyes, dry skin and lung irritation.
  • If the water chemistry is not kept in balance, chloramines will evaporate and cause a chlorine-like smell.

Pool bromine


  • Bromine does a great job at keeping bacteria, germs, viruses, algae, and other impurities away for a longer time than chlorine.
  • It has a lower pH level, so you won’t run into as many balance issues.
  • There is no strong smell, and less skin and eye irritation.
  • Bromine is better than chlorine for spas. It is more stable than chlorine at high water temperatures.


  • Bromine is generally a more expensive chemical to buy than chlorine.
  • Bromine takes a bit longer to activate. While it is easier on skin, it still has the potential to irritate.
  • It may not leave your water as clear as chlorine. At times it can leave a yellowish hue in the water even when clean.
  • Bromine requires more product for each application to get results.

Salt water swim spa


  • Salt replenishment is required less than chlorine or bromine.
  • Salt offers fewer health disadvantages than traditional chlorine. Salt is odorless and comes with fewer risks for allergies, eye and skin irritation.
  • Electricity turns salt into hydrochloric acid which is actually chlorine. It happens at a slower rate so there is less maintenance and it is better on your skin, eyes and swimsuit.
  • Salt systems tend to make the water “feel softer”.


  • Salt is more expensive than chlorine because it’s necessary to buy a generator to convert the salt.
  • Salt water pools can have high pH levels, therefore the levels must be carefully watched. Adjustments must be made when the levels rise or a pH regulator must be used.
  • Salt is corrosive, meaning the salt in pools can corrode and damage the system mechanics prematurely if it’s not washed frequently or if it’s not self-cleaning. It is also extremely corrosive which will affect wood decking, certain pavers, certain heaters, underwater lights, fixtures, stainless rails and components, some forms of masonry, and liners.
  • The initial cost of installation for saltwater pools is typically higher than the chlorine or bromine. It is also more complex and will require additional maintenance.
  • Salt may be harmful to certain environmental areas such as watersheds and groundwater well sites.