Hetty, oddly enough, I only add perlite, and that is coarse perlite, to my Phal. mix, never to my cattleya alliance mix. I use perlite, not for drainage, since my equal amounts of Douglas fir bar, horticultural charcoal, and coconut fiber gives me great drainage. I use the perlite to make the mix more dense, thus filling in the spaces that the other mix has. Phal. simply don't need the super aeration that cattleya's need. I do use perlite, at 1/3, for my terrestrial tropical plants' potting soil. Ken
