I know most of you buy your lava in big bags in your garden center. I need a smaller amount and found some in the grilling section of Home Depot. Is it safe to use? I don't think it has chemicals added? Also, what about broken up brick?
Brick should be chemically somewhat similar to LECA.
The big bags of "lava rock" are pretty cheap. I don't know how much the stuff for grills costs. Since it is used with food, it should be OK, but rinsing it and SLOWLY heating it up to 250 F will probably kill most.pathogens. I use the black lava rock, others prefer the red stuff.