Most of us have found that trying to maintain a habitat with a bottom substrate is a excercise in futility. Even though you may not feed your turt in that habitat, it still will poop and lose skin through shedding. All that debris falls to the bottom and gets lost in the sand or gravel and there it rots and fouls the water. You cannot plant plants in your habitat that your turt will not demolish or try to eat. Anything that is in his water gets tasted. The only reason turt owners put sand or gravel in their turt habitats is because it it pleasing to their eyes. Anything that is on the bottom, a turt will try to dig under or move with his front claws, usually in his quest for food. If a bit of debris is noted on a clean bottom, that is where the siphon comes in handy. Usually, the debris will cluster on the habitat bottom in certain spots due to the water flow around the habitat and that makes it a snap to siphon out that little pile without losing a gallon of water. Sand is a substrate for Soft-shelled Turtles. They relate to a bottom that they can hide in and owners of those turts take for granted that habitat cleaning is is gonna be tough. If that's your bag with a RES or any other aquatic turtle, you are a glutton for punishment and all I can say is, "Happy cleaning"! George