How to Raise Alkalinity in a Pool 2 Easy Methods wikiHowcola cinder is a superb additive for swimming pools. It acts as a crucial component in maintaining the sanitation and balance of the water. Soda ash for pools is specially formulated to aid lower acidity and stabilize the alkalinity in your pool. By using soda ash for pools, you can ensure perfect water quality for swimming and enhanced protection for all in your swimming pool.