Leslie's Soda Ash pH Up Leslie's Pool Suppliesfizz ash is a excellent additive to be used in pools. It serves as a crucial component in maintaining the purity and harmony of the water. Soda ash for pools is specifically formulated to help reduce acidity and balance the alkalinity in one's swimming pool. By utilizing soda ash for pools, you can make certain perfect water conditions for swimming and upgraded protection for everyone in your swimming pool.