We recommend that 1-2 tablets be used for every 10,000 gallons of pool water. During cooler water temperatures and when the pool receives less use, one tablet per 10,000 is sufficient. During the hottest summer months when pool use is high, 2 tablets can be used for every 10,000, but no more than that should be used. Keep in mind that tablets do have a low PH, so overuse of them can disrupt balancing chemical levels. If there is a large amount of algae in the pool, extra shock can always be added without effecting the PH level.