Water is essential for the health and well-being of your reptile. For most reptile species, a large, shallow dish should be provided in the cool end of the enclosure with clean, fresh water, which should be replaced at least once every day.
If you have a snake or tortoise, the bowl must be large enough to allow them to bathe. Should your reptile poo in the water, it needs to be replaced as soon as possible. Some reptile species (e.g. many chameleons) drink from water droplets or dew in the wild, so they will not recognise a dish of water as a water source to drink from. For these species, you will need to spray the enclosure or install a misting system or a drip system to provide the necessary water droplets.