Having trouble keeping your pH down? Use pH & Alk Potion to lower pH and slowly bring down total alkalinity to 80-100, typically within 1-2 weeks by using 1 tsp per 100 gallons every 2-3 days. Check alkalinity every 3-4 days until reaching 80-100. Then cut amount and use in half to maintain pH or use 1-2 cups white vinegar weekly to maintain pH.