True lava rock is fine. The grow rocks you are talking about is man formed lava rock anyway. BBQ lava rock is the same thing just make sure it's natural lave rock.
Zandor Reviewed by Zandor on . hydro pellets- I have seen on different videos that you can use the small clay balls to plant your plants in for hydro. Does anyone know of a good substitute for these-- maybe aquarium rocks or something -- I need something i can find locally like at walmart or home depot. Thanks Rating: 5