A little late in the game to be wondering this, but I thought I was all set. Today is day 19!! And now I'm not sure about the wells for water on the bottom of the incubator. It's a square styrofoam bator that I'm borrowing from 4H, so don't know what the manufacturer is. It has two separate wells and channels running along the bottom, one says thermal, the other circulated. I did have the thermal well filled through the first 18 days. I thought I was going to fill the circulated one on day 19, but after going over the paperwork, it's not clear to me if I should do that or not. Anyone know?