What Can Replace Chlorine in a Swimming Pool?

Chlorine is the most widely used form of sanitizer used to keep swimming pools clear, clean, and most importantly–safe.  Some people may not like the smell of chlorine.  Some people may have an allergy to chlorine.  Some people may just not like chemicals in general.  Here are some other methods some have used to sanitize their swimming pool water:

Salt Systems

This is kind of a trick answer because I have news for you.  A salt water pool is still a chlorine pool!  When one installs a salt board and a salt cell, they add the appropriate level of salt to their water.  You have to purchase a salt system.  Just dumping a bunch of salt in your pool water does nothing to sanitize.  As the swimming pool water is drawn from the skimmer and/or main drain, it passes through your various pieces of pool equipment.  If you converted to a salt pool, your salt system becomes one of them.  As the water passes through the salt cell, a process called electrolysis happens.  This converts the pool salt into chlorine at its most natural state.  A chlorine gas is produced.  This chlorine now sanitizes the water.

Some things to keep in mind when considering the switch to a salt pool.  Salt systems do not work when the water gets below around 58 degrees.  So come Winter, you will need to manually chlorinate.  Salt pools also require one to two times a week of muriatic acid.  This is because the chlorine gas that is produced is very basic, meaning high in pH.  So you have switched out filling your chlorine tablet floater weekly for adding acid weekly.  

Salt cells typically have a warranty of 3-4 years and can be as much as $1,200 to replace.  The boards also go bad and can get pricey.  So, in a nutshell, salt pools are no less money and no less work.  The water just feels better on your skin and you don’t have to purchase chlorine in the warmer months.


Ozonators, which are pool ozone generators, sanitize the water by generating ozone in the swimming pool water. Ozone is a blue colored gas that is made up of three oxygen atoms.  You don’t add it to your swimming pool.  It is added through being plumbed into your circulation system. The ozone is a germ killing machine.  It also kills bacteria and viruses.  Some say it even will kill the influenza and possibly the Covid-19 viruses.  Many people find this method to be hugely beneficial.

Even with Ozone, you still have to maintain a chlorine level of about 0.5-1 ppm.  So you are technically still not a chlorine free swimming pool.  These levels can be hard to maintain.  Most people end up with a higher ppm, which in turn, makes a chlorinated body of water.


Many people install an UltraViolet pool system onto their swimming pools.  The pool water passes through the filtration system first and then passes through the UV rays.  As the water flows through the graphite housing, a UV light then destroys bacteria, germs, algae and other unsightly microorganisms.  It accomplishes this by breaking through their cell walls.

As with an Ozone system, you still need to maintain a residual of chlorine of 0.5-1 ppm.  So while you are using a ton less chlorine, you still need to add some here and there.


Bromine was designed for indoor bodies of water.  The reason being is it cannot be stabilized with cyanuric acid like chlorine can.  So it burns off quickly in the sun’s UV rays.  It is quite popular in the spa communities because most people keep their spas covered during the day and only use the spa at night.  Bromine is ideal for this type of use.  It doesn’t gas off like chlorine.  It doesn’t have that chlorine-y smell.  It functions at a higher pH than chlorine does.  I do not recommend using bromine in any outdoor swimming pool.  You will spend a fortune on bromine and still probably never have a safe swimming pool.

Manufacturers are coming out with more and more alternative sanitation devices to help keep swimming pools safe.  Keep coming back to check up on the latest developments!  See you at the poolside!