We use lava rock extensively. It's the main ingredient in our mix for catts
and dens. We like it because it does not break down; this often means an
extra year between repottings and when we do repot, we don't have to remove
the old medium, making for less transplant shock. The downsides are that it
can tend to build up salts faster than, say, bark and doesn't buffer pH as
well. Unless your water quality is marginal to begin with, the salt buildup
problem can be avoided by proper watering [a thorough flush each time].

We do also use some lava rock in our oncid mix, but the proportion is less
because oncids don't like to dry out as fast and we need to keep them on the
same watering schedule as the other plants, so we add more coco-chips to
hold water longer.

Good growing,

--
Kenni Judd
Juno Beach Orchids

http://www.jborchids.com
"Shell91" wrote in message
y.com...
I am thinking of re-potting a few of my plants into lava rock. Any
thoughts
on the use of lava rock for all orchids? I am also thinking of getting a
few carnivoros plants to help keep bugs down around my orchids and other
plants. Does anyone else do this and if so how well does it work?

Shell