> Forgive me my ignorance, but after hearing about vermiculite for all
> that time I've been subscribed here, I finally decided to ask: What
> is it actually, and what good (or bad) does it do in a plant tank?
I *believe* it's a processed mica, but my memory could be playing
tricks on me. :-) At any rate, it's a soft, small particled, and very
light material used as a sort of 'filler' in potting soil mixes (since
it has many of the desirable qualities of soil such as fine particle size
and ability to hold water, but weighs less and doesn't seem to compact much.)
> Where can it be bought (garden-supply store, pet store, etc)?
You should be able to find it anywhere they sell potting soils, peat
moss, etc. (I got some at Walmart while shopping for shop lights to
mutilate to fit shorter tubes.... :-)