Can't Seem to Raise Humidity in my DIY Incubator

[MonaMona]

I built my own DIY incubator out of a styrofoam cooler, lightbulb, fan, hardware cloth, rocks, and tin pan to hold water. I've been trying lots of different things: different wattage of lightbulbs, more water, more rocks, fewer rocks, etc and I can't seem to raise the humidity beyond 15%. I'll be using the dry-hatch method for incubation, so I'm most concerned about getting that humidity up for lock-down. This is my first time hatching eggs, so any advice on my incubator is appreciated! I also wanted to go DIY to save costs before I buy an incubator so I'm patient with figuring out temps and humidity.

Below are pictures of my bator. The temp is high in the pictures as I had a 50 watt bulb in there in the hopes it'd evaporate the water faster but it just made it hot and dry. I've had better results with a 40 watt bulb--seems to keep the temps steady at around 100 degrees.

I have a feeling I need more ventilation. I'll drill holes in the bator if I need to--but where should the holes go? Thanks!

 

[Poultry parent]

A wet rag really helps raise the humidity

 

[BantyChooks]

You should not be running dry if your humidity is 15% w/o water. The "dry hatch" method should more accurately be called the "low humidity method". Most people in tabletop incubators have success with 30% humidity, but watch air cells or weigh to determine how the humidity should be adjusted from there. 15% will dehydrate the embryo and kill it.

Air cell chart:

 

[BantyChooks]

You have a fan in there yes? Try placing the water under the fan.

Also, have you checked your hydrometer for accuracy?

 

[MonaMona]

Thanks, BantyChooks! Yes--I've read a lot about dry hatching and know it's actually "low humidity" hatching, but, thanks! I think my problem may be the fan. I'm going to put the fan right into the bator and seal up its hole, then drill a couple holes on each side of the bator. I tried wet rag(s) and it did nothing but once I move the fan I'll see how it goes.

I've also got about 5 hygrometers and thermometers and tested them all and this one seems the most accurate.

 

[BantyChooks]

Thanks, BantyChooks! Yes--I've read a lot about dry hatching and know it's actually "low humidity" hatching, but, thanks! I think my problem may be the fan. I'm going to put the fan right into the bator and seal up its hole, then drill a couple holes on each side of the bator. I tried wet rag(s) and it did nothing but once I move the fan I'll see how it goes. 

I've also got about 5 hygrometers and thermometers and tested them all and this one seems the most accurate. 

Good to hear. Just making sure you wouldn't have a disaster of a hatch due to something easily fixed.

 

[MonaMona]

Update: the humidity is finally up! And the temps seem to be staying steady at 100! I'll keep an eye on this over the weekend but we may be good to go as of Monday! Thanks!!