All food dishes and water bottles should be cleaned daily. However, the entire cage should be cleaned every week, that is, if you are using a quality bedding such as CareFresh which absorbs urine and feces. This weekly cleaning should be very thorough, this is including the whole cage and all components like tunnels, food dishes, water bottles, wheels etc. with safe, soapy water and a mild disinfectant (I suggest vinegar and water) and drying them thoroughly before laying out fresh bedding. If you believe Nick's cage is rapidly becoming dirtier, and simply "smellier" you may also clean it twice a week. However, try not to clean it too much as Nick will get stressed which can bring upon many illnesses.