to the forum!
This thread is a few years old ... we have a more recently updated thread with info about gritty components for soil here
The thread "Soil for cacti and other succulents" in
Cactus and Succulents forum
I realize one word can mean different things to different people (and that is fine) but to me the word "grit" as it relates to succulents has to do with the size of the particles more than the specific components. To me grit occupies a middle ground between sand and gravel, like coarse sand or fine gravel.
