Foxfarm FX14066 Bush Doctor® Sledgehammer™™® Liquid Fertilizer, 1 QtBush doctor sledgehammer is a unique rinse formula designed to remove fertilizer buildup and encourage water movement through soil and soilless mediums. Sledgehammer helps release surface tension in the soil which will allow for optimum absorption of moisture and nutrition throughout the plants root system. Derived from an extract of the yucca schidigera plant called saponin. Sledgehammer is organic and can be used for both hydroponic and soil