How to Maintain the Proper Pool pH Level

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  • 1-2 hours
  • Beginner
  • 50-100

Maintaining your pool's pH level is an important part of pool ownership. PH is the measurement used to determine the water’s acidity. The pH scale has numbers from 0 to 14, with the ideal range for pool water between 7.2 and 7.8. As the pH number rises above 7, it indicates that the water is becoming more alkaline or basic. As pH decreases below 7, it indicates that the water is becoming more acidic.

Why the pH Level Matters

If your pH level is too high, the water is too alkaline and will begin to cause the formation of scale on various surfaces within the pool and equipment. If your pH level is too low, it is acidic. This will cause corrosion on surfaces in your pool and on your pool equipment. To maintain a balanced pH level in the pool and prevent potentially costly damage to pool surfaces and equipment, you need to use chemicals to either raise or lower the pH level.

Raising the pH Level

The pH level in your pool will tend to arise naturally due to environmental factors such as rainfall, swim load, and chemical balance. Should you need to raise the pool pH level, you need to add an alkali solution to the water. The alkali most commonly used is soda ash, also known as sodium carbonate. Most brands of this product have a scale on the back of the container that will help you to add the correct amount to bring the pH level up to the correct number.

Lowering the pH Level

This is the more typical action that you will need to take when working with your pool's pH level. In order to bring the pH numbers down, you will add an acid solution to your pool water. The two most common acids added to pools to raise the pH level are a liquid hydrochloric acid, also known as muriatic acid, or sodium bisulfate, which is a dry powdery acid. Since acids are caustic and can be harmful to your skin, you should never add acid to raise pH when the pool is in use or expected to be in use within 4 hours of adding the acid.

The acid should be added to a bucket of water and slowly added around the edge of the deep end of the pool, to ensure that you don’t score the walls of the pool with the raw acid. Acid can be hazardous to work with, so it is important to remember to add the acid to the water and not add water to the acid as it can result in serious burns.

Finally, you should not add too much acid to the water at one time. Too much can damage the pool surface, plumbing, and equipment, as well as lowering the overall alkalinity of the water. It is better to add small amounts at a time and then measure the pH level, rather than adding too much and causing damage to your pool systems.