If your pool’s pH is too low, use Pool & Spa pH Increaser. Also known as sodium carbonate or soda ash, Pool & Spa pH Incraeaser raises low pH and restores ideal swimming conditions. Pool & Spa pH Increaser will stop corrosion of pool equipment, increase the effectiveness of chlorine and other pool chemicals, prevent skin and eye irritation for swimmers, and stop etching and deterioration of plaster and grout. Rest assured that this product is 100% sodium carbonate/soda ash. We value our customers and we stand behind all of our products 100% with no questions asked. If you are not pleased, call or email us with your order number, and we will reimburse you in full. Directions: Using the chart on the label, measure and pour Pool & Spa pH Increaser directly into the pool and wait for the pH to rise. Test pool pH again after five or six hours