Aqua One pH Down Powder Aqua One pH Down powder allows you to decrease pH to optimal levels. pH is the measure of alkalinity and Acidity within a liquid. pH is measured on a scale from 0 to 14 with 0 - 6.9 is Acid, 7.1 - 14 is Alkaline. It is critical to test and adjust the pH in your aquarium: For a newly set up aquarium whenever a water change has been performed As part of your weekly maintenance Features: Reduces alkalinity and increases acidity Powder is instantly soluble in aquarium water Suitable for tropical and coldwater Directions: Use a pH test kit to test pH levels of your aquarium. Where the pH reading is too high, use Aqua One pH Down to lower pH Use the 2g per 40L of aquarium water to lower pH by 0.4 per 24 hour period Use the 2g spoon provided, measure the desired amount of pH down into a clean container Place some aquarium water from your aquarium into the container and stir to mix the solution Once Dissolved, add the mixture to your aquarium slowly over a 15 minute period Pour the mixture near the outlet of your filtration system Re-test the pH after 12-24 hours and make adjustments as necessary Aqua One Product Number - 92085