Maintaining high humidity in an incubator during hatch

Around day 19, when the first chicks could potentially start to pip, it's time to raise the humidity in your incubator to 65% or more.  High humidity during hatch is essential to lubricate your chicks as they do the hard work of wiggling around, pecking their way out of their shells.  At the same time, you need to keep the vent at least a third of the way open because these hard-working chicks need more airflow to feed their struggles.  But the open vent tends to lower the incubator's humidity, so that's the solution?

You can buy evaporating card to stick in your incubator's wells, but the cheaper method is just to use a piece of cloth.  If you place part of the cloth or evaporating card in the well and let the rest sit along the bottom of the incubator, water will wick up into the extra surface area, resulting in more evaporation and higher humidity.

For an even bigger dose of humidity to counteract the vapor lost when you open the lid, heat up some water until it's steaming but is still just cool enough to stick your hand in.  I poured some of this warm water into the wells every time I opened the lid of my Brinsea Octagon 20 incubator, which meant that the humidity rebounded within a minute of me opening and then reclosing the lid.

Most websites will tell you to be as hands-off as possible during the hatch, opening the lid only once every six to eight hours.  Now that I've had a bit of experience, though, I disagree.  I've learned the hard way that if a newly hatched chick rolls a neighbor egg so that its pipping hole is facing the floor, the chick still in its shell can expire before you're allowed to open the lid again.  Knowing some tricks to maintain high humidity while still being allowed to open the lid seems to be key to higher hatch rates.

After several rounds of trial and error, I figured out the best way to incubate chicks.  You can read the blow by blow experimentation here, or splurge 99 cents on my ebook for the more refined solutions.