The pH of an aquarium is an often disregarded yet crucially important factor in maintaining a healthy aquatic environment. Such pH levels can experience instability due to biological or chemical activities, yet with Fritz pH Lower, the pH can be lowered to the optimal state for the fish's well-being. Adjusting the pH has a direct effect on the fish's health and resistance to disease, in addition to helping the aquatic filter's efficiency. Directions & Dosage: For every 20 gallons, add in 5 ml (1 tsp/cap) of the product. Prior to dosing, test the pH level. Depending on the water's initial acidity, multiple doses may be necessary to reach the desired pH. Wait around 10 minutes, then recheck before adding further pH Lower. Where fish are present, the pH should only shift by 0.2 daily.