The whole bin is 85F!? Or just the warm spot? Because that sounds quite high!
You really need a heat gradient for your snakes (if you don't already), that varies by about 10F - so for example, 75F on one side, 85F one the other. If I am misunderstanding, I apologize.
You have a plastic bin with water and high heat, so it will cause condensation. You should have a hygrometer to see what the humidity is in the bins to know if it is too high (or too low). You can always have more air flow in the tubs to make the humidity escape (ie. more air holes).
I seriously believe you should turn down the heat strips lower if the entire tub is at 85F. Personally, my corn only goes to her warm side once in awhile to digest, and most of the time she prefers her cool side, which is around 75F.
If you are unable to have a heat gradient right now, I would suggest lowering the temp by 5F or so. When I was waiting on my thermostat to come in the mail I had my tank at 78-80FF, and that was enough for Syd to digest and be comfortable and herself.
Good luck!