AAA-50-8602 (SCP) - NO DEPOSIT MURIATIC ACID-MA4 Gallon No Deposit Muriatic Acid is a pool chemical that can be used to maintain pH balance and lower alkalinity in pool water. Muriatic Acid can also be used as a cleaning agent on pool surfaces and tiles. At the end of the pool season, use Muriatic Acid to clear out any mold or algae leftover in your pool.