When is too much humidity a problem?

I switched my ball python into a new cage today and the humidity seems to be pretty high. It's about 68-72% humidity. I live in South Florida so it's always very humid.

So my question is, is 70% too high? If so, how can I lower it? Here is a link to the cage I have him in http://www.npicages.com/36_rack.html
I'm using newspaper as a substrate and have a medium sized water bowl that is big enough for him to soak if needed.

Thanks!

When mold starts to grow. You have an issue.

Somebody on here has said that a BP in the wild usually has ~80% humidity. We keep them lower than that for who knows what reason. As long as there's no condensation and there are enough holes for proper airflow, there's really not a huge risk of your snake getting an RI. You could try a smaller water bowl, if you wanted, or blow a fan at the enclosure to bring it down.