If the pH is at 7.0, how much soda ash should be added to increase it to 7.4?

To increase the pH of pool water from 7.0 to 7.4, soda ash (sodium carbonate) is commonly used as a pH increaser. The pH scale is logarithmic, meaning that small changes in pH correspond to larger changes in the concentration of hydrogen ions in the water.

When the pH is maintained at 7.4, it is considered optimal for swimmer comfort, equipment longevity, and chlorine effectiveness. The amount of soda ash required can vary depending on the specific pool volume and other factors, but for a typical residential pool, an increase from 7.0 to 7.4 generally requires about 8 ounces of soda ash for 10,000 gallons of water.

Adding 8 ounces of soda ash will increase the pH adequately without overshooting the desired level, helping to maintain proper water chemistry and ensure a safe and enjoyable swimming environment. This correction helps stabilize the pH closer to the recommended range while making it easier to manage other chemical balances in the pool.