Hatcher is 15" x 26" x 12" (floor space 15" x 26"). I checked my hygrometers and one read 78% and 2 read 73% after 24 hrs in baggie w/salt water *testing*. I'm ready to move in a group of Day 18 eggs tonight and even with almost the entire floor surface is water and humidity seems low (for that much surface area). I'm reading 60%, 55%, and 56% from same hygrometers. Why so low? I'd like the humidity to be 65%, but there is no where else to put water. The 'vents' are six 1/4" holes just below the level of the rack. Am I looking at this wrong? Thanks! Lisa HA! In the time it took to load the pic, I came up with a theory.