I think changing substrate will help with humidity a lot. If you dont want to do the whole RHP route, try using two water bowels. One under the heat, one on the other side.
...and if you're not having much luck with your bowels, you might try bowls!!
~~McKinsey~~
"Men have forgotten this truth," said the fox. "But you must not forget it. You become responsible, forever, for what you have tamed."
~The Little Prince; Antoine de Saint Exupery