pH

• The amount of pH added to the pool depends on the pH reading. If the reading is 7.6 to 7.8, 1-1/4 oz. of muriatic acid is added per every 1,000 gallons of water. For a reading over 8.4, 3 oz. of muriatic acid is added per every 1,000 gallons
  
  

Total Alkalinity

• When the total alkalinity in the pool is high, muriatic acid is used to lower the total alkalinity. The ideal reading for total alkalinity is between 8 and 150 parts per million (ppm). Decreasing the total alkalinity 10 ppm requires 2.56 oz. of muriatic acid per every 1,000 gallons of water. Lowering the total alkalinity 50 ppm requires using 12.80 oz. of muriatic acid per every 1,000 gallons of water.
  
  

Warning

• When using muriatic acid to lower pH or total alkalinity, you need to dilute the acid 10 (water) to 1 (acid) in a bucket. Never add water to acid. Add acid to water. Pour the solution in the deep end of the pool, avoiding contact with the walls and fixtures in the pool.