Though facilities have used it for years, saline chlorination, otherwise known as on-site sodium hypochlorite generation or simply chlorine generation, is a little-used technology in the U.S. commercial pool market. However, the process has been used successfully for more than 30 years in countries such as Australia and South Africa.
One reason for the success is the bather comfort that saline chlorination provides. In essence, it converts the pool water into mineral spa water, thus reducing skin, ear and eye irritation.
In the U.S. pool market, the technology has predominantly been used in residential pools, where salt is added directly to the water and chlorine is generated through an electrolytic cell. This form of chlorination has become so popular that statistics show more than 70 percent of newly constructed residential pools opted for saline chlorinators last year.
Until recently, the technology has not been widely adopted for large commercial pools and aquatics facilities in this country. This is a result of two primary factors: the significant investment required for initial equipment purchase (anywhere from $2,000 to $25,000, depending on the pool size) and the unfamiliarity of saline chlorination in the U.S. commercial pool industry.
In addition, because commercial pools require more chlorine than a residential pool, manufacturers, designers and builders have been limited by how much water they could treat.
Now new technology allows the treatment of virtually any size commercial pool — some can even chlorinate larger water bodies such as waterparks. Also, leasing options have made the equipment much more affordable.
In an on-site saline chlorination system, regular salt is converted into sodium hypochlorite through the process known as electrolysis, by applying power to the electrodes of an electrolytic cell. Because chlorine is produced within the system, handling and storage issues are reduced. Salt can either be physically thrown in the pool or automatically put in the water with a salt-saturated feeder.
Saline chlorination systems can produce up to 25 pounds a day. In a three-year period, that’s the equivalent of 28,000 gallons of 10 percent bleach, or approximately 40,000 pounds of 65 percent calcium hypochlorite. When the logistics of ordering, storage and handling of that much product are considered, it is easy to see why chlorine generation makes so much sense for commercial pools.
Saline chlorination systems also produce 100 percent equivalent chlorine, meaning no waste product, and are continuously super-chlorinating all the water passing through the electrolytic cell.
Most commercial pools are sanitized by bleach, calcium hypochlorite and trichlor. Though effective, each of these chlorines has its own assets and liabilities.
Handling of commercial chemical products often is listed as the No. 1 concern for operators, with safety and storage concerns as the second. Both of these concerns are minimized by using saline chlorination because the only raw material that is handled by on-site maintenance personnel is salt.
In addition, facilities have seen price increases in all types of chlorines over the past three years, making budget projections and monthly costs difficult to predict. Saline chlorination costs are much more predictable.
Salt prices are more stable because it is so widely available around the world in a variety of forms, including ocean water. Right now it costs about 8 cents a pound. The primary cost is the investment in equipment. Whether you buy it outright or lease it monthly, your costs will remain stable.
Each year facilities such as Atlantis in Nassau, Bahamas, and Bridgemill and Morehouse College, both in Atlanta, convert to salt chlorination. Maybe they’re on to something.