Honestly I get the best yields from Rye, but when I use verm I do a verm / brown rice flour substrate. It makes really nice cakes if I just want to do a simple PF tek.

When I case I don't use verm for my casing layer, I just use a potting soil. I only use the verm for inoculation, so casing really doesn't add much cost or time for me.

I dunno, like I said I get the best yields from Rye with a nice soil casing, so no vermiculite is needed at all. I may just stick with that tek. It's just a little less convenient if you want to do an easy batch in short order.

And yeah acolon, I agree on the perlite. I don't see how you could even make an effective cake using perlite... I've only used perlite as humidity control base layer.

I might try Rye with brown rice flour and see if I can't get a nice compact consistency that would make an effective cake. Never tried that combo, but I bet it would have enough nutrients that once your cakes are flushed out you could break them up, case 'em and potentially get a couple more flushes out of them... :idea: Hmm... I guess I'm just thinking out loud here.