I found my hovabator runs with too high a humidity (apx. 70 %) only using the center reservoir. It is also difficult to see if it has any water in it...especially with the auto cradle and I had to open the incubator to add water. So I worked out the following set up: I'm sure I'm not the first to figure this out. I manipulate the humidity by the size of the dish and by partially blocking one vent hole with the other one open. I set the dish under one hole, so I can fill it with a straw and surround it with eggs so it doesn't move. I place the temp/ humidity gauge where I can see it through the window and have a backup for redundancy. I threw out the thermometer that came with the incubator...it was off by a mile. The dish needs to be cleaned about once a week because a film develops and the humidity drops. The gauge readings are with the top off. It would normally read 99 deg and about 40% humidity. I only have to open the incubator a few times in 3 weeks. Candle and lock down at 18 days. This batch didn't too well...it was a shipped batch and I was working out the system. Last batch of about 12 eggs....only 5 fertile eggs (my rooster died)...4 hatched and one developed fully and never pipped. Still fine tuning it.