When making BHO what type of butane do you use, how many times has it been refined, and how many ounces? Is triple refined good enough, or do I need to find a more refined one? I saw a 12 pack of 3 oz cans of colibri premium butane for $75. Seems pricey to me but I don't know how much it usually should go for. Plus if I need to use 3 or 4 cans I don't think it would really be worth it.