Can you use red lava yard-rocks for grow medium ?

[latewood]

Iâ??ve heard people mention â??lava rocksâ?? as a grow medium, instead of Hydroton. Are they talking about special lava-rocks sold at a grow store, or the red lava-type rocks used for landscaping, that people use in their front yard in place of grass ?
The yard kind is probably very cheap compared to Hydroton (they probably sell it by the cubic yard like soil). What I wonder is:
1) does it release minerals into the solution that would raise/lower the pH ? and
2) does the rock being red mean itâ??s got a lot of iron in it, which is toxic to plants (except in micro dosages) ?
Has anybody grown in red yard rocks?

hey carolina boy...look here, lave rock is usually added to the bottom of the pot in so9il plants to increase drainage...If you tried to use it in dwc/hydro it would work, I think but, you would not hold moisture as much, It won't hurt anything, and I think it's red, because they call it 'lava rock'...hydroton is the shit...It is reusable and provides anexcllent medium for hydro...Imho.lw