Looking for some information about our Sun Mar composting toilet. Bought used and have figured out the general workings, but curious to talk with folks who have used these and can anwer some of our questions: e.g. does the electric model fan ALWAYS have to run, or has anybody used an alternate material in their mix for the bulking material (peat moss, wood shavings) as opposed to the manuyfacurer's mix, etc... Thanks in advance!! Mic