A photo or drawing of your enclosure showing vents etc might be helpful. Heat dosent penetrate downwards too far. about 1 ft at max imo. I had similar problems with humidity with my older enclosre , talleer and a bit larger. water is just too far from the heat, even directly beneath.
I ended up getting a new smaller enclosure, sacrificing luxurious space for climatic comfort. P.s , by larger water bowl do you mean deeper or larger water surface area? A larger water surface area will help because the larger the surface area, the more evaporation going on. cheers. :wink: