How to Raise Your Pool’s Alkalinity with Bicarbonate of Soda: A Simple Guide

Maintaining the correct alkalinity in your swimming pool is crucial for the health of the water and those who enjoy it. Alkalinity acts as a buffer for pH levels, which means if your pool’s total alkalinity is within the proper range, it prevents drastic fluctuations in pH that can lead to corrosion, scaling, and discomfort for swimmers. If you find that your pool water’s alkalinity is below the recommended range of 80-120 parts per million (ppm), you will need to raise it to achieve a balanced water chemistry.

Effective substance for increasing pool water alkalinity

Sodium bicarbonate, commonly known as bicarbonate of soda in Australia, is an effective substance for increasing pool water alkalinity. Bicarbonate of soda is gentle on the water, providing a gradual increase in alkalinity without causing a significant spike in pH levels. When you use bicarbonate of soda, you ensure a stable and comfortable swimming environment while safeguarding the pool’s surfaces and equipment from damage.

Before you add bicarbonate of soda to your pool, test your water to determine the current alkalinity level. This initial step is essential to calculate the amount of bicarbonate of soda needed to reach the desired alkalinity range. The general rule of thumb is that for every 10,000 litres of pool water, roughly 100 grams of bicarbonate of soda will increase alkalinity by about 1 ppm. However, it’s vital to proceed with gradual additions and to retest the water after each treatment to avoid overshooting the ideal alkalinity level.

Understanding Pool Alkalinity and pH

In ensuring the health of your swimming pool water, balancing alkalinity and pH is crucial. It not only affects water clarity and quality but also plays a significant role in the longevity of your pool’s surfaces and equipment.

Chemistry of Pool Water

Your swimming pool’s water chemistry involves a delicate balance of different chemical levels. Total alkalinity (TA) acts as a buffer, absorbing fluctuations and stabilising the pH of your pool water. An optimal alkalinity range lies between 80-120 parts per million (PPM). The pH level, which measures the acidity or basicity of the water, should ideally sit between 7.4 and 7.6 to match the natural pH of human eyes and mucous membranes, thus offering a comfortable swimming environment.

Importance of Balanced Alkalinity

Balanced alkalinity is critical for maintaining a stable pH level. It protects pool surfaces and equipment from corrosion and ensures that chlorine works effectively as a disinfectant. Stable alkalinity also provides a more pleasant swimming experience as it prevents irritation to swimmers’ skin and eyes.

Consequences of Low Alkalinity

Low alkalinity can lead to acidic pool water, characterised by a pH level below 7.0, which can cause corrosion of metal surfaces, etching of pool liners, and discomfort for swimmers. It may also lead to the formation of stains and cloudy water, which can be unsightly and indicate a larger problem with water quality.

Alkalinity versus pH Levels

Alkalinity and pH are inextricably linked, but they are not the same. Think of alkalinity as the supporting player that helps maintain a steady pH level. If the alkalinity is correct, the pH is more likely to be balanced as well. However, a pool can have high alkalinity levels while having a low pH, or vice versa, due to the presence of other chemicals and the unique water chemistry of your pool.

To adjust your pool’s alkalinity, you may use baking soda (sodium bicarbonate), which is a common alkalinity increaser. A test kit is essential to measure current levels before you start treating your swimming pool water. Remember that each adjustment you make should be followed by testing, ensuring that you are incrementally moving towards the ideal chemical balance for a safe and stable swimming environment.

Testing and Adjusting Alkalinity

Proper testing and adjusting of your pool’s alkalinity are essential for maintaining water balance. This section will guide you through the process of testing pool alkalinity, interpreting the results, and carefully raising the levels using sodium bicarbonate.

How to Test Pool Alkalinity

To determine the current total alkalinity (TA) of your pool water, you will need a reliable pool test kit or testing strips. Ensure you follow the manufacturer’s instructions accurately when performing these tests. It’s best to conduct the testing away from the pool’s jets or skimmers and at least 30 minutes after the pump has been running.

Interpreting Test Results

Once you have completed your test, compare the colour on the testing strip or read the measurement on your test kit’s gauge. Total alkalinity is measured in parts per million (ppm), and for pool water, the ideal range is typically between 80-120 ppm. If your readings are below 80 ppm, it indicates low alkalinity which can lead to unstable pH levels.

Preparing to Adjust Alkalinity

Before you proceed, make sure you’re wearing safety goggles and gloves as a precaution for handling chemicals. Verify your pool volume to calculate how much sodium bicarbonate you will require. A pool calculator can be beneficial in determining the correct dosage. Ensure the pool pump is on to adequately circulate the chemicals.

Guidelines for Raising Alkalinity

To raise the alkalinity, utilise sodium bicarbonate (baking soda), which is a safer choice compared to sodium carbonate (soda ash), which can drastically change the pH levels. The usual dosage is:

  • 1.6 kilograms of sodium bicarbonate per 50,000 litres of pool water will raise the alkalinity by approximately 10 ppm.

Dilute sodium bicarbonate in water and add it to the pool, spreading it evenly over the surface. Wait for at least 6 hours before retesting the alkalinity to allow full circulation and integration of the chemical. Adjust further if necessary, following the same method, until you reach the optimal range.

Practical Application of Bicarbonate of Soda

When introducing bicarbonate of soda, commonly known as baking soda, to your pool water, precision and safety are key to achieving the desired increase in alkalinity without adversely affecting the pH balance.

Steps to Increase Alkalinity with Bicarbonate

  1. Test your pool water using an accurate test kit to determine the current alkalinity level.
  2. Calculate the required amount of baking soda. Generally, for every 10,000 litres of pool water, 1.5 kg of baking soda can raise total alkalinity by approximately 10 parts per million (ppm).
  3. Slowly add the bicarbonate of soda directly to the pool or via the skimmer, ensuring the pool pump is running to promote even distribution.
  4. Wait for at least 6 hours after application before re-testing the alkalinity of the pool water to confirm the adjustment.

Safety and Handling of Chemicals

  • Wear safety goggles and gloves to protect your skin and eyes during handling.
  • Ensure proper ventilation if working in an enclosed space to prevent inhalation of dust.
  • Store baking soda in a dry, cool place, away from other pool chemicals to prevent contamination and reactions.

Maintenance After Adjustment

  • Weekly testing of your pool’s water is crucial to ensure stable pH and alkalinity levels.
  • A regular maintenance schedule prevents issues such as cloudy pool water or pH bounce, which can occur if alkalinity levels are not kept in balance.
  • Monitor the pool’s pH as well, since altering alkalinity can also impact pH levels.

Common Misconceptions

  • Baking soda vs. soda ash: Baking soda raises alkalinity with less effect on pH, whereas soda ash mainly increases pH.
  • Cloudiness: Sometimes after adding baking soda, pool water can become cloudy; this is usually temporary and should clear up with the filtration system running.
  • pH bounce: Inconsistent chemical levels can cause pH levels to fluctuate widely, termed ‘pH bounce’; maintaining proper alkalinity can help stabilise pH levels.