Q2. No idea.

Q3. Should be noprob. The mycelium should keep it all together nicely.

Q4. Because the verm. keeps the humidity level good. Still....i acctually never use verm. I use the 9er tek (ie. only brownrice).... Depends on the nutrients...and there ability to hold humidity at a good level...

The great thing about whole seeds (rice, birdseed, etc) is that there is plenty of air between the grains, not really any need for the vermiculite.

However, I went the other direction, a bit more vermiculite, much less rice. Its working quite well.

Acctually putting less rice in your substrate means putting less nutrients in the substrate.

Less nutrients = less food for the mycelium and shrooms = less yield.

- LillSkit -