Yes there was a very contentious thread once on another gardening forum I belonged to talking about bleach and polycarb. Also some people say that the strength of the Physan you get now is not the same as it was back in the day...but I think it is still just as effective as ever. I have used it on orchids too...and I have used it at a dilution of 1-2 tsp/gallon to kill the various molds and fungi and algae that form on the leaves of some plants because I had (before I turned it off and started hand watering) an overhead sprinkler system. You have to wash it off but it works well. I am going to disinfect some large growing Anthuriums and Palms tomorrow.
