Do not put holes in the containers, it ruins the humidity. The air needs to flow around the containers not through them.

Snakes do not urinate a liquid, they produces a solid white urate substance. I'm not sure what your snake is passing, but it is not normal for a snake to pass any kind of liquid on a daily basis. Are you sure it is coming from the snake and not just tipping the water dish? Does it smell? Is it thick?