Add pH Up when nutrient pH is too low. Add pH Down when pH needs to be lowered. Includes a pH test indicator that is easy to use. Package measures 4.8L x 2.7W x 5.8H. Keep your soil at the proper pH level with the General Hydroponics pH Control Kit. Designed to help you raise healthy plants, this kit includes pH Up to increase the pH level of your soil, pH down to decrease the level of pH in your soil, and an easy-to-use pH test indicator that allows you to test your soil whenever needed. About Hydrofarm, Inc. Celebrated as the nation's oldest and largest manufacturer of hydroponic equipment and grow lights, Hydrofarm has made professional-grade equipment available to all since 1977. All grow lights and electric components are UL listed, unlike many competitors' products, meaning you get years of reliable and safe use out your high-intensity lights. All products are covered by a one year warranty, at the least. In some cases Hydrofarm ensures the performance of their products for five years.