None. That's a hardware problem.
The answer may shock you.
They can't change anything
FORE!
One but you should have seen the bulb it must have been THIS big.
Off-by-one error.
A full one, in case he gets thirsty, and an empty one, in case he doesn’t.
None. That's a hardware problem but have you tried turning it on and off again
None that's a hardware problem