API PH Down Fish Treatment 118ml pH Down is designed to lower the pH of aquarium water where testing has shown pH to be at an undesirable level. It lowers pH and makes aquarium water more acidic. It is fast-acting, colourless, easy to use and will not cloud or colour the aquarium water. It is phosphate-free and nitrate-free therefore will not encourage algae growth Directions Determine the pH of aquarium water with an API test kit To lower pH, add 1/2 teaspoon (2.5 milli litre) for each 95 litres of aquarium water For larger aquariums, add 1 teaspoon (5 milli litre) for each 190 litres of aquarium water Take another pH reading before dosing again with pH Down Some fish may be more sensitive to pH adjustments greater than 0.2 in a 24 hour period, so changes of this magnitude should be done with extreme care Tips Some water is high in mineral ions, such as carbonate and bicarbonate, which strongly buffers aquarium water and can resist a pH change or cause pH rebound. In these situations, repeated dosing may be necessary to lower pH.
