I was planning on spawning to manure/vermiculite but then I read this. according to the mushroom grower's handbook, chapter 4, page 106, end of the second paragraph---

Quote:
When 10% peat moss is added [to the substrate mix], the contaminnation rate by Trichoderma is decreased by 50% and yields increased by 30%.


So I decided I wanted to make a substrate out of peat moss, manure, and vermiculite. But I have no idea what the ratios should be of calcium carbonate (to adjust the ph of the moss)/peat moss/manure/vermiculite. Could I use the 50/50 casing tek. for this as it is - the crushed oyster shell and + manure with out having to adjust the amount of calcium carbonate. Or since there would be more substrate from the manure would there be more calcium carbonate required? Also would putting more then 10% moss negatively effect what the quote above sates? Here is the tek I am talking about http://www.shroomery.org/54/50-50-Casing-Tek

use poo, vermiculite and coir...works great