When swim spa owners begin to explore ways to reduce the amount of chlorine they use in their pools there are only a few end products that this road will lead to. Arguably the single best method to reduce chlorine demand in pools is through the use of ozone - while chlorine is not ideal perhaps, there are very good reasons it is used in swim spas. Certainly, this is a situation where chlorine is the lesser of two evils.
The dangers of unsanitized pool water can not be understated - you need to understand the importance of swimming spa water being safe. If you are trying to operate your pool completely free of any form of chemical sanitizer then I hope you wear a lab coat to work every day because if you do not then you are exposing yourself to risk for no reason. A savvy, educated pool owner does not seek to operate a pool "chemical free" but instead to operate the pool with the absolute minimum amount of chlorine sanitizer to ensure bathers are safe and protected at all times. That should be your goal, and if it is, the information on this page will help you accomplish this goal.
Why Do I Need A Chemical Sanitizer Like Chlorine?
There are very few options for things you can add to your pool water that will meet all of these requirements. Chlorine is, by far, the most popular one. Every form of chlorine alternative (chemical sanitizer as options ) such as UV, ozone, pool rocks, magnets, ionization, natural water treatments and many others are missing one, if not all of these qualities. There are many products on the pool and spa market that claim to improve (decrease) chlorine demand in pool water however few, if any, of these products can meet the requirements as established within the industry. While ozone is no exception, it is actually one of the very best options.
If you attempt to operate your swimming hot tub with any method other than those established to meet all four of these criteria, such as chlorine or bromine sanitizer, then there is at least 1 way you are open to potential for dangerous water conditions to develop - potentially many ways.
How Does Ozone Work In Swim Spas?
Ozone is an oxidizer. It is an unstable molecule, O3, and tries to stabilize itself by attaching to organic debris and oxidizing it during this process. An oxidizer such as ozone also reacts with chloramines in pool water (spent chlorine) to oxidize the chloramine. As a form of protecting bathers against possible dangers in the water, ozone meets almost all of the main criteria - almost.
Ozone does not have the ability to build a residual in the water. In simple terms what this means is that there is no reserve of ozone waiting in the water for some bacteria or organic debris to show up. That is how chlorine works - free chlorine is just floating, in reserve, in the water waiting for something to show up. If organic debris, skin, sweat, oil or any other contaminant is introduced to the water, the chlorine is ready and waiting. Almost all potential threats in swim spa water are dead in less than 60 seconds when exposed to anything over 1 ppm of free chlorine. This is an important point to understand since this value is the specific reason that ozone is not suitable as a stand-alone solution to pool water treatment.
Ozone does not last long - the unstable nature of the ozone molecule, the very thing that makes it effective in swim hot tub water treatment, is the reason it is not able to hold a residual in pool water. Within about 20 seconds ozone will return to 02 - oxygen so it must be created and added to the pool within a short period of time for effectiveness. Without a residual in the water this causes a number of concerns such as sunlight causing algae to grow on pool surfaces. Of primary concern is that any contaminant introduced to the pool will live unrestricted in the water until such time that it passes through the filtration system and/or encounters an ozone bubble in the pool.
