Here is another tip; it is deadly to fish. Do not use on or near fish tanks or ponds. Southern Ag makes a similar product called SA-20 and calls it a disinfectant which is a better term than fungicide. I bought some when I couldn't find Physan as the two are comprised of the same stuff. I took it to the orchid club meeting for one of my learning moment talks and the guest speaker (a well known grower) chimed in about what it would do to orchids if sprayed directly. I would not use it on any part of the plant including roots. It is strictly to be used on hard surfaces.
Jim
