Managing humidity in a cheap incubator?

[Katiedidnt58]

I will be doing it again, no matter what it's too exciting not to. But next time hopefully not quite so nerve-wracking

 

[Indio Gigante Lover]

I've never had an incubator that automatically adjusts humidity, so I've found what works best with mine. Humidity is ONLY determined by surface area that comes in contact with the air. You could have a 4oz glass filled to the rim, and humidity would be exactly the same as with a 4oz glass with 1/8" of water in it. Knowing that, you can "calibrate" your humidity by putting in a 2 liter bottle cap about half full of water & waiting to see how much that raises your humidity. Then you can figure how many bottle caps of water surface you'll need to achieve desired result. If your conditions are extremely dry & you end up with too many bottle caps, you could go with something slightly larger than the caps, but too big gets risky for chick drowning.

Using caps makes it really easy if say, you had your humidity perfect, then fill incubator with eggs & 12 hours later humidity starts to climb - just remove a cap or 2 & it quickly drops. I'd advise to never follow incubator instructions that say to fill it's reservoir(s) with water! There's no way you're going to tip the thing on it's side to drain out water with eggs in it. The caps make small incremental adjustments very easy