I am working on my humidity in my new dickey incubator. i have the humidity setup, with a water pan in the incubator and a tub on top. how do you adjust the humidity with this? even if I add more water I would think the surface area would be the same and thus the humidity would be the same. My humidity is at 40 percent at the moment. that is fine for incubating but low for hatching. what ways can I increase/control humidity with this type of setup? thanks!