I have followed the Brinsea user manual so far with respect to humidity. I have kept one half of the center are with water and then last night filled up the entire center column to up the humidity for hatch as they instruct. So I filled it up last night, tomorrow night will be 21 full days. I do not want to lift the lid to add more water, but I found during this process that the water evaporated from 1/2 of the center cylinder within a few days. My question is: from your prior experience, how many days will water remain in the center cylinder (remember I filled up both halves as they instruct for added humidity) before it runs dry? I don't want to raise the lid to mess up the humidity but don't want all the water to dry up if they end up being a few days late. Thanks in advance.