This is my second year now of hatching. I see a lot of people struggling with humidity. I don't struggle at all! I use an old washcloth fold it in half & then again, placing it right under one of the red plugs. Then as I need I just add a little warm water to the cloth. I put mine in this morning at 5:30 to raise my humidity up to 70%, it is now 10:00 at night & my humidity hasn't budged. I use warm water, and when doing chicks I get it good and wet then squeeze wring it out before placing it inside. For ducks I place it then douse it with warm water till I see it float a tad on top. I hope this helps someone out there!