I just finished my second hatch in my homemade incubator, with disappointing results. The first batch to pip turned out beautifully, and the rest are all dead in the shell, fully formed. After the first hatch, I thought it was a humidity problem, so I bought a hygrometer and vowed never to open it during lockdown again. (Last time I set button quail and coturnix at the same time, so I had to open it to get the buttons out). I really struggled to keep the humidity up while this batch was incubating. I have a wide tray in the bottom under the wire "floor" (probably takes up 2/3 of the bottom) with a tube fed trough a hole to add warm water. I had one large sponge in there, but when it came time to lock down I lifted the eggs out and wrapped them in a warm towel while I lifted up the wire floor to add another sponge. Before lockdown the best humidity I could get was in the 30s, and during lockdown was high 40s to low 50s. The weird thing is that relative humidity around here is generally at least 55%, but within about a day it dropped that low within the 'bator. I set 39 eggs. I pulled out four that just had what looked like a giant yolk inside, and four early quitters, and seven hatched--leaving 24 that died at the end. What should I do? Cut up a third sponge to stick around the edges of the two in there to increase surface area? (There isn't room to add a whole third sponge). Should I take out the tray and fill the whole bottom with water? Close up some of my ventilation holes? It is a forced air incubator, if that makes a difference.