Ozone & Salt Pool Systems
OZONE SWIMMING POOL MAINTENANCE SYSTEMS
Ozone swimming pool technology sanitizes pool water by utilizing the natural sterilizing action that is produced when oxygen molecules are broken apart to produce ozone. The ozone is then forced into the swimming pool water, where it oxidizes any contaminates, before returning to its natural state, oxygen.
Ozone (O3) is basically oxygen (O2), with an extra oxygen atom that is produced by passing air over a specific ultraviolet (UV) light or through corona discharge (high voltage). Ozone is one of the strongest oxidation agents available and will bind quickly to every component that it contacts.
Because ozone binds so quickly and has a short half life, ozone does not leave residue in swimming pools or spas. This causes two important problems: it is very difficult to measure swimming pool water sanitization without expensive equipment and there is no sanitizing effect in the swimming pool once the pump is turned off.
Ozone generator manufacturers claim their systems are effective stand-alone swimming pool sanitizers. However, Bayside Pool Service has found that ozone generators are insufficient to sanitize swimming pools and spas in Florida’s harsh climate, unless used in conjunction with another pool sanitization product.
When Ozone is used in conjunction with a salt water swimming pool maintenance system or with an automatic chlorinator, it performs effectively. If it is used with a normal chlorine system, use of chemicals is reduced dramatically and levels of residual chlorine in a swimming pool can be relatively low, without incidence of algae.
For best results, Bayside Pool Service suggests using an ozone generator in conjunction with a salt water maintenance system. Although this configuration may be expensive to install (approximately $1500), it would enable you to run the salt cell for much shorter periods, thereby extending its life while keeping residual chlorine levels to a minimum.
ADVANTAGES OF OZONE-BASED SWIMMING POOL CLEANING SYSTEMS
- Powerful oxidation naturally sanitizes swimming pools and spas.
- Ozone systems use fewer swimming pool chemicals.
- Oxidation is safe, natural, and leaves no residue after oxidation.
- Oxidation tends to clean “scum” line left on a pool.
- Oxidation saves money on chemicals over time.
DISADVANTAGES
- Swimming pool sanitization is difficult to measure.
- No residue left in the pool and, therefore, no cleaning action when the pump is off.
- Some people don’t like seeing bubbles in the water returns.
- Ozone generator systems are more expensive to install than traditional swimming pool water filtrations systems.
SALT WATER POOLS
Salt chlorine generator systems sanitize swimming pools by converting salt into chlorine, which kills pathogens and bacteria before returning to its former state, salt. The system converts salt to chlorine by passing the dissolved salt in the pool water through a small chamber (salt chlorinator cell) installed along the swimming pool’s water circulation system. These cells contain parallel titanium plates coated with either ruthenium or iridium. The plates are electronically charged to produce hypochlorous acid(HOCl), and sodium hypochlorite (NaClO) from the salt.
Salt water pools are not actually chlorine-free; they use a chlorine generator instead of directly adding liquid chlorine or chlorine tablets to the swimming pool.
With most salt chlorine generator systems, a salt content of around 3,000 ppm (parts per million) is desirable, but this can range from 1,800 to 4,000 ppm, depending on the system requirements. As a reference, ocean water has a salt content of approximately 35,000 ppm and humans generally have a salt taste threshold of around 3,500 – 6,000 ppm.
In theory, there is no need to add salt to a salt chlorine generator system, but in actual practice most swimming pools do need salt added consistently due to splash-out, backwashing, dilution from rainwater, and leaks. Generally, most people swimming in salt water pools feel the water is softer, has a lower chlorine scent, and they have fewer incidences of dry skin and burning eyes.
Although salt chlorine generator systems have many benefits, there are many issues that some pool stores neglect to mention when selling these systems. The following is a list of advantages and disadvantages, along with some practical advice if you already have a salt chlorine generator system.
ADVANTAGES OF A SALT CHLORINE GENERATOR SANITAZTION SYSTEM
- Water feels smoother in a salt water swimming pool.
- Salt water has a lower chlorine scent.
- Salt water pools cause less burning of the eyes and itchy skin.
- No need to buy and store chlorine with a salt water swimming pool.
DISADVANTAGES
- Salt water swimming pool sanitation systems can be expensive, between $600 and $1500 to install.
- Salt chlorine generator cells do not last for a long period of time. Generally, you can expect them to last between two and five years, with three years being average.
- Replacement cells for salt chlorine generators cost approximately $500 to $700.
PRACTICAL ADVICE
- Cleaning the salt chlorinator cell too often with acid reduces the life of the cell by stripping the coating on the plates.
- Cleaning the salt chlorinator cell with a highly concentrated acid reduces the life of the cell.
- Salt water chlorine generator cells have a tendency to allow Ph to rise. Check the water chemistry regularly.
- Stabilizer is a key component of salt chlorine generator systems and needs to be checked regularly.
- Running the salt chlorine generator for long periods without enough salt in the swimming pool can strip the coating off of the cell.
- There are still occasions where shocking the swimming pool with extra chlorine may be advantageous.
- When swimmers smell more chlorine than normal and have eye irritations, they tend to assume there is too much chlorine in the pool. In fact, what they may be experiencing is organic contamination (chloramines), not chlorine. The remedy is more chlorine, not less.
- Although some salt chlorine generator systems have a “shock” or “boost” button, this does not mean a swimming pool can be shocked by the salt chlorine generator. Salt chlorine generator systems cannot produce enough chlorine over a short period of time to significantly impact algae.
