Calcium scale prevention and pH control
High calcium content can lead to scale formation, as well as cloudy water. Scale forms when calcium and carbonates crystallize on the pool walls around the waterline surfaces and equipment. This problem is compounded by a high pH. Borates keep the pH from creeping upwards to help prevent scaling. With an increased installation of pools with salt chlorine generators, borates have become even more important, as scale can reduce the life of the cell plates in the generators.
By maintaining borate levels at 50 ppm, salt cells last much longer. Service technicians agree the salt conversion cells can easily last a decade. Even customers who ensure their pool water is balanced only get five to six years out of an equivalent cell without borates. The salt cell lasts longer when borates are used because they bond with the calcium in the water, allowing it to remain cleaner and producing less scale. Although scale does form in some cases, it is a much softer scale which is easier to remove. Plate damage is also minimized, as less acid is required to clean the cell plates.
Due to the high pH at the surface of the cathode plates, scale formation is more likely. In fact, it is important to note scale formation will occur inside the salt chlorine generator, even if the pool water is properly balanced. Service teams should start all their new pools with approximately 30 to 50 ppm of borates in the water, which normally lasts between one and two years. After about a year and a half, they usually need to add a little more borate product to get the level back up into that range.
Additional benefits of borates
Borate-based products also inhibit the reproduction of algae. This is a huge benefit for service technicians, as pool owners who use borates rarely have problems with green water—even after it rains in the summer and temperatures rise to 37 C (100 F). Those who do not use borates in those conditions will routinely see their pools turn green overnight. As summer rains and warmer temperatures increase, service professionals should always test for borates as part of regular water maintenance programs. Some pool professionals find borates also help to keep the pores of the pool plaster clean and algae-free.
Although borates are mainly a tool for pH and algae control, pool owners also like the look and feel they give the water. This product increases the water’s refractory index. More light is reflected, which gives the pool more sparkle. Finally, borates help to improve the overall bather experience. All borates can be considered derivatives of boric acid B(OH)3, the active ingredient in eye drops. This soothing ability translates into pools and spas treated with borates. Borates are a mineral salt, so they help make bathers’ skin feel softer and help reduce red eyes from swimming.
