How to Increase the Total Hardness in a Vinyl Pool

Swimming pool water has many different chemical levels that are constantly monitored and balanced to provide a safe environment for swimmers. One of these water levels is Total Hardness. Total Hardness is the measure of calcium salts dissolved in the pool water. Having too low of a hardness level can cause calcium to be leached from pool surfaces which causes the surface to become pitted. In order to raise the hardness level of pool water, the chemical calcium chloride is added directly to the pool water.

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Keep your pool water healthy and safe for swimmers.

Step 1

Test your pool's water for Total Hardness content and record the results. An ideal hardness level is between 200 and 400 parts per million. If no home testing kit is available, take a sample of pool water to your local pool professionals for testing.

Step 2

Divide the appropriate amount of calcium chloride into three doses. Typically 5 lbs. of calcium chloride are used per 10,000 gallons of water to raise the hardness level by 50 parts per million.

Step 3

Pour a dose directly into the pool water and allow the pool to circulate for at least 2 hours before applying another dose. Proceed until all doses are applied to the water.

Step 4

Take a sample of your pool's water and test the hardness level. Reapply calcium chloride to the pool as needed until the hardness level is in the recommended range.