I clean about every two weeks and always after a shed because my snake makes a mess! However, I use paper towels and they are harder to spot clean. Some times I can't stand watching my bp slither all over his urine and feces. So that is why I clean about every two weeks. When I clean during those times though, I don't bleach, I just replace the paper towels.

When he sheds I usually bleach everything (hide, water bowl, log). He sheds once a month. So that is when I really clean the tank.