I am soon going to be outdoor guerilla growing with a pot. This will be my first grow and I hear a lot about air to water ratio etc.. I have been told that perlite is good for airing the soil as well as vermiculite. Can people please tell me what ratio to use in a 10 litre pot? AND ALSO does this look fine for soil use because it looks like they're using this perlite for mushrooms: Perlite 4ltr bag | eBay Cheers !!