The Benefits of Borates

Borates help pools with salt chlorine generators

One of the primary reasons borates have gained popularity among pool service professionals is their ability to control corrosion in a saltwater pool environment. For pools with salt chlorine generator systems, a large amount of pool-grade salt is added to establish a concentration of about 3,000 to 5,000 parts per million (ppm). It is important to maintain the appropriate salt concentration, as using too much can increase the potential for corrosion. Pools with salt chlorine generators continuously produce sodium hydroxide (NaOH) when the sodium chloride (NaCl) is broken into free chlorine. Unfortunately, NaOH has a pH of approximately 13, which will quickly increase the pH of the pool water. The continuous addition of NaOH results in a never-ending pH increase. If this is left unresolved, the high pH will lead to corrosion of the pool components.

Borates have a buffering ability that allows pool water to remain at a more neutral pH level for longer. This allows chlorine to be more efficient and effective at sanitizing the water. Borate products are also easy to use, as they are available in powders and slurries that can be added directly to the pool. Borates help prevent corrosion and scale on equipment while also controlling pH levels in the pool water.

Corrosion prevention

The electrolysis that occurs in a salt chlorine generator can damage plating on handrails, light niches and other metal components. Borates create another buffering system for the water that eliminates these effects. Many pool professionals agree borates are a good companion product to salt chlorine generators because they help simplify water and equipment maintenance. It is worth the consumer’s extra investment in a borate product, especially when their pool uses a salt chlorine generator to produce sanitizer. Borates add an anti-corrosion effect to help ensure against rust on equipment, accessories and fixtures around the pool.

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 upward 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 that 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 produce less scale. Although scale does form in some cases, it is a much softer scale that 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. It is important to note that 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 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 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 keep the pool plaster's pores 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 a bather’s skin feel softer and help reduce red eyes from swimming.

Better balance with borates

Balanced pool water is one of the easiest ways to ensure chlorine will keep water sanitized. Borates allow pool water to remain at a more stable pH level for a longer period, resulting in lower chlorine consumption. Frequent and consistent testing of chlorine, using a home testing kit or test strips, is imperative to make sure the sanitizer levels are at the correct levels.  Without testing, one may needlessly add too much chlorine, as only 1-3 ppm of it is typically needed for good water quality.

For pools that use chlorine generators, there is a case to be made for adding borates to the water to ensure those generators are not working overtime and causing harmful side effects to the pool and to the generator itself. In general, borates improve the wellness of all pool types.

Many new pool owners have entered the market over the past two years and we, as an industry, need to ensure they enjoy their new investment without headaches. With service technicians stretched to their limits, borates can help minimize maintenance between service visits and keep customers happy.