Iā??ve heard people mention ā??lava rocksā?? 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 itā??s got a lot of iron in it, which is toxic to plants (except in micro dosages) ?
Has anybody grown in red yard rocks?
grow4fun Reviewed by grow4fun on . Can you use red lava yard-rocks for grow medium ? Iā??ve heard people mention ā??lava rocksā?? 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 Rating: 5