Off the top of my head, I believe they're the same or closely related
chemicals and would probably do the same. One orchid site
http://www.kkorchid.com/1chemicals.htm lists Physan 20 as a replacement for
RD20.
Gary
"bb" wrote in message
...
On Fri, 7 Feb 2003 17:53:00 -0500, "Gareth Wills"
wrote:

Physan is easy to get hold of. A small amount goes a long way.

Are you familiar with a product named RD 20, and if so, would it do
the same thing as Physan?

Thanks
bb