API pH Up 16oz.

API Pond pH UP slowly raises the pH of pond water, making it more alkaline, without harming delicate pond fish or aquatic plants. It slowly neutralizes acid substances that contribute to low pH, which can stress pond fish and suppress the activity of your pond’s natural biological filter. 

API pH Up & pH Down Dosage
To Lower the pH Add 1 teaspoons per 50 gallons of pond water. Carefully mix desired dose with 2 gallons of pond water in a plastic bucket and distribute evenly around the perimeter of the pond.
To Raise the pH Add 2 teaspoons per 50 gallons of pond water. For best results, add to water flow.
pH should not be raised or lowered more than .5 units every 24 hours. Do not treat the pond more than once in a 24 hour period.
Repeat treatment as necessary.