How to regulate humidity without a hygrometer

[wjhuskey]

Does anyone know of a way to regulate humidity accurately without a hygrometer? This may be hard since humidity may vary in houses, not to mention I'm incubating in my basement. I know more water in the incubator means more humidity so do I just fill up the water chamber and make sure it stays full throughout the first 18 days to maintain the recommended 50% or is it not that easy? And add a sponge the 19th day to increase humidity to 80%? In other words is there a system to go by to know you have the right humidity according to the amount of water you have or is a hygrometer something I MUST get?

 

[cluck5]

I have 3 hygrometers and none of them measure properly. I have even tested them. It would be a good idea to have one and then calibrate it (check on incubating/hatching 101). But I have read here, that you should weigh your eggs to figure out if your humidity is to high/low in your incubator. There is info on the April hatch along from member "bittersweet" that will tell you how to do this (you'll need a good scale).

 

[Pele]

Just go to your local pet store and visit the reptile section. They have humidity guages there for pretty cheap.

 

[cluck5]

wjhuskey: Sorry the member's name whom I got the formula for weighing the egg to test humidity loss was bitterroot not bittersweet.
Also, as PELE said, hygrometers can be inexpensive, but I think it is important to test/calibrate them as they could be totally inacurate.