Azomite is volcanic ash that is mined. It was laid down in a lake bed millions of years ago and now they claim it is very good for plants. Throw a little in your next batch of soil-less and see if you notice anything? It shouldn't harm the plants at all.
Azomite is 12% Al!!!!! Folks see positive response from it due to the Ca in it. Then the plant gets intoxicated. Don't ever use Azomite!
I have seen large farmers lose it using this product.