Physan 20 is a broad range disinfectant, fungicide, virucide, and algaecide

 Physan 20
     Physan 20 is a broad range disinfectant, fungicide, virucide, and algaecide which controls a wide variety of pathogens on hard surfaces and plants. It controls disease-spreading organisms which can be carried from plant to plant by using contaminated pots, flats, seed beds, soil, tools and human hands. We always use it in the water when we pre-soak our potting mediums. Great stuff!

The producer of Physan 20, Maril Products Inc., has WONDERFUL information on their website detailing the uses of Physan 20. For use on orchid, go to http://www.physan.com/orchids_physan.htm