I am wondering if you have found it easier to maintain your humidity with a sponge or filling the water reservoirs?
Also how often do you have to either re-wet the sponge or re-fill the reservoirs?
I always used the reservoirs until day 20, when I added a wet sponge. Worked well for me.
I just filled the reservoirs when they looked low, every couple or three days, I suppose. The sponge doesn't need to go in until the eggs are about to hatch.