Physan 20 Fungicide, Algaecide and Disinfectant ConcentratePHYSAN 20 is a broad range disinfectant, fungicide, virucide, and algaecide which effectively controls a wide variety of pathogens on hard surfaces and plants. Its applications include greenhouses, hard surfaces, lawn and turfgrass, seedlings and cut flowers, decorative fountains, pools and birdbaths, and plants. Physan 20 Greenhouse Disinfectant can be used in a variety of hydroponic applications to: Prevent the development of disease Kill algae that