We use a lot of lava rock. It doesn't break down, which means less frequent
repotting and, unless we're dividing the plant, easier repotting as well.
We use RO water and have no salt buildup problem. Kenni

"BruceM" wrote in message
news
Having just recently been suckered into getting more orchids (Cattleya's
and Dendobiums) at Wal Mart......... I have noticed these from Wal mart
are usaually in a 3 inch square pot Volcanic rock and newspaper. Are
there any advantages to Volcanic rock, other than it is cheap and
plentifull in Hwaii.

My reading research shows it holds water well. Will it wick water? The
thought of using it like Prime agra for hydroponic has crossed my mind