How to Add Soda Ash or Sodium Bicarb to a Swimming Poolseltzer cinder is a great additive to be used in aquatic facilities. It is a essential element in preserving the purity and harmony of the water. Soft drink is particularly formulated to assist decrease acidity and stabilize the pH levels in your swimming pool. By using soda ash for pools, you can guarantee perfect water quality for swimming and improved protection for all in the pool.