You can often buy rice hulls already carbonized or burned to ash, or you can make your own using this simple system to save money
Making Carbonized Rice Hulls (CRH) | Geopolymer House Blog.
You can often buy rice hulls already carbonized or burned to ash, or you can make your own using this simple system to save money
Making Carbonized Rice Hulls (CRH) | Geopolymer House Blog.