Borax. Sodium borate. Sodium tetraborate. Disodium Tetraborate. This boron compound has as many uses as it does names. While its claim to fame is as a household cleaning agent (particularly as laundry detergent to brighten whites), its versatility extends to surprising uses such as the main ingredient in slime. But did you know that borax can also be a pool owner’s saving grace?
Maintaining a sparkling blue swimming pool can be a cumbersome process: clean out skimmer basket weekly, check the water level, clean the filter, vacuum the bottom of the pool, and balance the chemistry of the water. Cut out the frustration of attempting to increase the water’s pH levels without affecting its alkalinity. Borax acts as an effective pH buffer and helps prevent algae growth in swimming pools. Plus, it will leave your water looking sparkly and feeling soft.
What is pH?
The pH scale measures a liquid’s hydrogen ion concentration (the relative acidity or alkalinity of a solution) ranging from 0 to 14, with 7 being neutral. Pure water is a neutral substance because the number of positive hydrogen ions produced is equal to the number of negative ones. This equilibrium makes water neither an acid nor base.
As hydrogen ion concentration increases, pH value decreases; therefore, a substance with a low pH value has a high concentration of hydrogen ions. Acids have a low pH value (between 0-7 with 0 being the highest level of acidity) while bases have a high pH value (between 7-14 with 14 being the highest level of alkalinity). This means that acids have a high concentration of hydrogen ions, but bases decrease the concentration.
Interesting fact: A solution can’t have pH without being aqueous—a solution in which water is the solvent—which is why you don’t see companies advertising the pH of their vegetable oil or alcohol (because they have no pH value).
The Importance of pH in Swimming Pools
A swimming pool’s pH levels must always be in balance to ensure a fun, safe day in the water. The optimal pH for pool water is 7.4, but a good range would be between 7.2-7.6.
Attempting to swim in a pool with a pH level below 7 would be an uncomfortable excursion. Eyes and skin exposed to acidic water will become red, irritated, and itchy. Your pool would also suffer the consequences as the acidic water would damage your mosaic tiles, which, in turn, would promote algae growth.
When the pH level is higher than 7, your pool will have cloudy, murky water that can clog filters and pipes. This alkaline water will cause eye irritation and diminish the benefits of chlorine (requiring you to use more, thus wasting more money.)
Benefits of Using Borax
Borax is tremendously effective at stabilizing alkalinity and acting as a pH buffer in swimming pools.
Traditionally, pool owners have relied on baking soda (sodium bicarbonate) and soda ash (sodium carbonate) to maintain their pools’ pH levels; however, these chemicals have adverse effects. While they do raise pH levels, they also raise the total alkalinity of the water. Increased alkalinity causes the pH level to fluctuate, which defeats the purpose of adding chemicals to stabilize the water.
Unlike the carbonate compounds, borax prevents the pH from fluctuating without increasing the total alkalinity of the water. It also protects against algae growth by maintaining the pH at a constant level, allowing the chlorine to sanitize the water effectively.
Once dissolved, borax remains in the water permanently and does not evaporate. This ensures sparkling, soft water to swim (plus, chloramine does not form as quickly). You’ll be using less chlorine, which means increased savings.
How Much Borax to Add to Your Pool
If you’re wondering how much borax to add to your pool, conduct a pH test. You will need to raise the pH level if it is lower than the ideal range of 7.2-7.6.
Use 20 ounces of Borax for every 5,000 gallons of water in your pool (this is just an estimate as different chemical factors may require a different amount for your pool). For higher accuracy, use an online pool calculator to find that perfect amount.