Pool water chemistry depends heavily on the power of hydrogen, or pH, which is a logarithmic scale measuring the relative acidity or basicity of the water. A reading below 7.0 indicates acidity, while a reading above 7.0 indicates basicity, often referred to as alkaline water. Maintaining the correct balance is important for managing the water’s interaction with bathers and the pool’s physical structure. This measurement significantly influences the overall health of the swimming environment.
Understanding the Impact of Low pH
When the pH level in pool water drops below the recommended range, the water becomes acidic and causes several adverse effects. One immediate consequence is bather discomfort, as acidic water irritates the mucous membranes of the eyes and strips natural oils from the skin. This often leads to redness, burning, and itching for swimmers.
Low pH water also becomes corrosive, posing a threat to expensive pool equipment and materials. Over time, acidic water degrades metal components like pump seals and heat exchangers in heaters. It also damages the pool’s interior surfaces, such as plaster and grout, accelerating wear and tear significantly.
Additionally, a low pH negatively impacts the effectiveness of chlorine sanitizer. Slightly acidic conditions cause chlorine to become overactive and dissipate too quickly from the water. This means the sanitizer is not available to properly neutralize contaminants, resulting in poor water quality and the need for frequent chemical additions to maintain a safe environment.
Testing and Target pH Levels
Before attempting any chemical adjustment, accurately determine the current pH level using a reliable testing method. These methods typically include color-matching liquid reagent kits, test strips, or digital water testers, each providing a measurement of the water’s chemical balance. The results are the basis for calculating the precise amount of chemical needed to bring the water back into the acceptable range.
The universally accepted ideal pH range for swimming pools is narrow, sitting between 7.4 and 7.6. This range minimizes irritation to swimmers while maximizing chlorine efficiency. Maintaining pH within this range is important for both swimmer comfort and equipment longevity.
Adjusting pH is closely tied to the pool’s Total Alkalinity (TA), which measures the concentration of alkaline substances that buffer against sudden pH changes. Before adjusting pH, the TA level must be checked and corrected if necessary. A proper TA level, ideally between 80 and 120 parts per million, helps stabilize the pH, preventing it from fluctuating wildly after treatment.
Choosing the Right pH Increaser
When the goal is to directly raise a low pH reading, the chemical of choice is Sodium Carbonate, commonly known as Soda Ash. This compound is effective because it acts as a strong base, quickly neutralizing acid and driving the pH upward. It is widely available in pool supply stores and formulated for this purpose.
A secondary, milder option is Sodium Bicarbonate, or Baking Soda, which primarily functions as an alkalinity increaser. While raising Total Alkalinity helps stabilize and gently elevate the pH over time, it is less potent than Soda Ash for immediate and significant pH adjustments. Therefore, Soda Ash is the preferred choice when a large or rapid increase in pH is required.
Handle all pool chemicals, including Sodium Carbonate, with care to prevent accidental exposure or injury. Users should always wear appropriate protective equipment, such as gloves and eye protection, when measuring and mixing the product. Chemicals must be stored in a cool, dry, and secure location away from other reactive substances.
When using any pH-raising chemical, always read and adhere to the manufacturer’s directions for dosage and application. Over-dosing can quickly push the pH too high, leading to scaling and cloudiness. This necessitates a subsequent adjustment with an acid, so accurate measurement is essential for a balanced result.
The Step-by-Step Application Process
The initial step involves precisely calculating the required dosage based on the pool’s volume and current pH level. Use a reliable pool calculator or the chemical manufacturer’s dosing chart for this calculation. Accurately determining the pool’s volume in gallons is necessary to ensure the chemical treatment is effective without overshooting the target range.
Once the correct amount of Sodium Carbonate is measured, it must be properly prepared before introduction. The powder should first be pre-dissolved in a bucket of water to ensure even dispersion. This prevents the concentrated chemical from settling on the pool floor and damaging the surface finish. Always add the chemical to the water, never the reverse, to minimize splashing.
After the powder is fully dissolved, disperse the solution slowly and methodically around the perimeter of the deep end. Pouring in the deep end allows the solution to mix more thoroughly with the greater body of water before reaching the skimmers. Avoid dumping the entire amount in one spot, which can cause localized chemical imbalance.
Immediately after dispersion, the pool’s circulation system, including the pump and filter, must run continuously for a minimum of six to eight hours. This continuous operation ensures the chemical is thoroughly mixed throughout the entire body of water, providing a uniform pH adjustment. Proper mixing prevents water stratification and ensures the pH reading taken later is representative of the entire pool.
After the initial circulation period, wait another six to eight hours before retesting the water. This waiting period allows the chemical reactions to fully stabilize and the new pH level to settle completely. Pool adjustments should always be incremental; if the target pH is not reached, make a second, smaller adjustment and repeat the entire process to prevent overcorrection.