WATER TREATMENT: OZONE, UV AND SALT SYSTEMS
Hot tub manufacturers offer different water treatment devices which include ozone, Ultraviolet (UV) and salt systems (Chlorine/bromine generators).
Ozone is a device which oxidizes organics in the water and helps clarify and keep the water fresh. The advantage of ozone is that it reduce demand for chemical sanitizers and makes it easier to maintain the water.
UV is a sanitizer that deactivates bacteria and microorganisms with germicidal UVc light. The benefit of UV is that it reduces demand for chemical sanitizers and destroys chemical resistant microorganisms.
Salt Systems are devices that automatically generate chlorine or bromine when salt is added to the water. The benefit of salt systems are that you do not have to manually add chlorine or bromine. The concern with salt systems is that it creates a very corrosive environment which can shorten the life of spa components (jets, heats, pump seals, etc.) In addition, many communities have banned salt systems from being drained into the sewer system.
Originally, most hot tubs were designed with pressure style filter cartridges. This style pushes water through the filter and has a by-pass valve that opens when the jets are on high speed and allows water to by-pass the filter. Unfortunately with this type of filter system the spa water is not being filtered at the most important time which is when you are in the tub with the jets on high speed. Additionally it is more difficult to open the cartridge to remove the filter.
While this style of filter is still widely used, most manufacturers have switched to the suctions style filter which filters the water regardless if the jets are on low speed or high speed. The best suction style filters will have a 1 micron pre-filter and 10 micron cartridge filter.