Is pH Important in Swimming Pools?

Defining pH

• The term pH refers to the level of acidity or alkalinity present in your pool water. The higher the pH level is over the "7" mark, the more alkaline the water. The lower it is under the "7" mark, the more acidic the water. Too far in either direction -- alkaline or acid -- can cause undesirable growths in your pool, a reduction in the chlorine's effectiveness. At extreme levels it can cause damage should it come in contact with skin.

How to Test

• You must purchase or obtain a pool testing kit to check the pH level in your pool water. Fill one of the vials on the kit full of water, then add between two and five drops -- depending on the test kit -- of testing fluid to the water. Mix the water, then compare the color to the color chart in the kit. Match the shade the water turned to the appropriate shade on the color chart to determine the pH level in the water.

Treating Low pH

• Low pH means your pool water is acidic, and must be treated with a base material to neutralize that acidity. Soda ash is the most often-used method of treating low pH in pools. Mix the needed amount of soda ash in a bucket of water and add the water to your pool while the pool filter is running to ensure the ash-water mixes well. You may need to treat the pool several times to raise the pH to optimal levels, depending on how low it was to begin with.

Treating High pH

• A high pH level means your pool water is more alkali -- or "base" -- than it ought to be. The common way of treating a high pH value is through a process called "shocking." Mix an appropriate amount of pool shock -- shock is essentially an extremely potent form of chlorine -- in a 5-gallon bucket of water. Add the shock mixture to the pool while the pool filter is running to mix it up properly. As with the soda ash treatment, you may need to shock the pool more than once to lower the pH value sufficiently.