Dry acid, or sodium bisulfate, is a white crystallized granular substance used to lower swimming pool water pH.
What is Dry Acid for swimming pools?
Dry acid is also known by its chemical name as sodium bisulfate. It is produced as a white, dry granular form by mixing sulfuric acid and sodium hydroxide together. The result is the acid salt sodium bisulfate, and water.
For swimming pools, dry acid is used to lower pH and decrease total alkalinity in pool water. In pools with high pH or total alkalinity, adding dry acid can help maintain the water balance of a swimming pool. Although liquid muriatic acid is another chemical that performs similarly, dry acid is more user-friendly, is less caustic and does not damage surfaces as easily if spilled or splashed accidentally. It can also be stored in a wider range of conditions, although dry acid must be handled with care.as it is corrosive.
Dry acid is added directly to well-circulated swimming pool water, and will readily dissolve. Testing swimming pool pH and also testing total alkalinity should be done immediately prior to adding dry acid and ideally again after about six hours later, making sure to test within 24 hours.
- Wikipedia: “Sodium Bisulfate”, http://en.wikipedia.org/wiki/Sodium_bisulfate