The Green Knight, a non-cartridge Hydroponic Dechlorinator, is designed to reduce Free Available Chlorine (FAC) in tap water when filling hydroponic nutrient tanks. Depending on the pH of the water it may also reduce chloramine compounds. The Green Knight Hydroponic Dechlorinator is now molded in white UV resistant polypropylene. The Green Cap which distinguishes it from the Gard'n Gro is polypropylene plastic. The Green Knight has been engineered to reduce water flow to 2 GPM. This is to maximize water contact time with the media.