Test the alkalinity of the pool using the alkalinity test strip first. Dip the test strip in the water and pull it out. Compare the color of the test strip to the color chart with the kit. The ideal range for alkalinity is 80 to 150 parts per million (ppm).
Add sodium bicarbonate to the pool water to raise the alkalinity. Use the directions on the package for the number of gallons of water in the pool and how many parts per million you need to raise the alkalinity. Use muriatic acid according to the directions on the package for the pool size and how many parts per million you need to lower the alkalinity in the pool.
Test the hardness of the water using a hardness test strip second. Dip the strip in the water and pull it out. Compare the color of the strip to the test kit color chart. The ideal range for hardness is 250 ppm.
Raise the hardness level of the water by using calcium chloride per the directions on the package for the size pool you have and the parts per million that you need to raise the hardness. Use anhydrous trisodium phosphate to lower the hardness following the package directions.
Test the pH of the water last. Use a test strip for pH. Dip the strip in the water and pull it out. Compare the color of the strip to the color chart in the kit. The ideal pH range is 7.2 to 7.8 ppm, but, ideally, you want the pH to be 7.4 to 7.6 ppm.
Add soda ash to the pool water if the pH is low. Use muriatic acid if the pH is high. Follow the package directions for the size of the pool and parts per million that the pH must be raised or lowered.
Use a metal sequestering agent as the final step to getting rid of calcium in the pool. The sequestering agent removes the scale buildup in the pool. If you don’t have scale on pool walls, floors or equipment and fixtures, you can skip this step. If you do have scale, follow the directions on the package per the size pool you have before adding the sequestering agent.