so maybe this is a silly question to some. does fresh water mean straight from the tap or water that has sat to let the chlorine out? because when i was younger and was told to do water changes for fish, no one said the water had to sit and I assumed it was straight from the tap which was incorrect. some people say change water everyday some say up to every week for a snake. how much water would a 13" S dekayi need,size of bowl and change how often?