I use 40 gallon breeder, glass enclosures that have slide-on screen tops. I have 11 inch x 11 inch jungle heat pad under the the cool side hides and 11 inch x 11 inch desert heat pad under the hot side hides. Also, on the hot side I have overhead ceramic heat emitters (up to 100w). They are all controlled with dimmer switches.

This setup allows me to maintain 90 degrees in the warm side hides (measured with a probe thermometer), 80 degrees in the cool side hides (also measured with probe) and ambient temperatures (temp of the air measured at ground level in the middle) of 78 degrees (measured with thermometer/hydrometer combos that read 60-70% humidity).

Now, I have a screen tops and an over head heat sources, this evaporates the moisture in the air thus lowering the humidity. To remedy this I use wet towels over the rest of the screen. This keeps the humidity and temps just the way I like it.

I feel that I do not require a dish that my snakes can soak in because they already have all the humidity they need. However, I am unsure if it would be a good idea to have a smaller dish if you cannot maintain high enough humidity.

For instance, I 'rescued' my first snake from my brother who did not have a clue what the humidity was because he did not even measure it. I would guess that if she had a bowl to soak in, she would have shed in one piece. Having said that, if you have to choose a large water dish or a humidity level that best reflects their natural environment, I would go with the humidity.

Jimmy