I just got 2 big bags of Grow Stones from a hydroponics store that was reducing inventory. I didn't pay very much but I looked it up on the web and it was pretty expensive it seemed to me. It's a recycled glass product. I like it a lot. Especially the nice grey with maybe a tinge of blue. It contrasts well with clay pots which I use a lot. The statistics on the media is pretty impressive too. Anybody else tried it?