Hydrologic Replacement Carbon Filter for Tall Boy and Tall BProvide pure water to your plants with Hydrologic Replacement Carbon Filter for increased quality and yield. KDF85 is a highly effective media that filters water and pre treat water. In addition, it has excellent chloramines and chlorine removal potential that help you get rid of the harmful contaminants and other volatile organic compounds that can damage your plant health. You can use the carbon filter for well water or spring water sources. KDF85