Usually i spot clean/refill water every day or every other day. The snakes on cypress mulch get a full change every month or every other month. Sometimes they mess it up alot but if its a slow month as far as pooping and shedding ill stretch it for 2 months. The one on newspaper gets the paper changed whenever i noticed pee/poo. Since it only takes 5 min usually ill do this once or twice a week.