How Does a Low pH Affect Chlorine Levels in a Pool?
- The effects of low pH in a swimming pool mainly have to do with chlorine levels and swimmer comfort. For one, a swimming pool that suffers from low pH often has little or no chlorine availability present. Chlorine quickly dissipates whenever a swimming pool's pH is too low. And when there's no chlorine in a swimming pool's water, potentially serious bacteria and organic matter can contaminate a pool. Also, low pH sometimes can lead swimmers to develop severe eye irritation.
- The pH in a swimming pool's water is a measure of that pool's relative alkalinity and acidity. When a pool's pH is too low, the pool is considered acidic. When pH in a pool is too high, the pool is suffering from excess alkalinity. A perfectly neutral pH is 7; swimming pool water should not deviate too greatly from that figure. Fortunately, it doesn't require a great amount of effort to maintain proper swimming pool pH balances.
- The recommended pH range for a swimming pool should be between 7 and 8. A good range of pH in a swimming pool to shoot for is 7.2 to 7.8. The best range of all for pool pH is 7.4 to 7.6. A swimming pool should be slightly alkaline, which is why the optimum pH level of 7.4 to 7.6 works so well. And when a pool's pH is optimum, its chlorine levels tend to be optimum as well.
- When a swimming pool's pH level is low, it can be raised by adding an alkalinity-increasing agent to its water. While marketed under many different brand names, the most common alkalinity-increasing agent is soda ash, which is the common name for sodium carbonate. One lb. of soda ash or 1 lb. of sodium bicarbonate (baking soda) is typically used per 30,000 gallons of pool water to raise pH to 7 or above.
- Monitoring chlorine and pH levels in a swimming pool is relatively easy if you use a good all-purpose pool test kit. Follow the instructions specific to the pool test kit, and either raise or lower pH levels as needed. To lower pH in a swimming pool, its alkalinity must be lowered by adding a reducing agent. The most common alkalinity lowering chemical agent for swimming pools is muriatic acid (MA). Always use MA only according to directions.