How to increase humidity?

[Aroha]

I've just bought an incubator and have set it up to make sure all is working correctly. The temperature seems stable between 37.5 and 38 but I can't get the humidity higher than 48%. The instructions aren't very clear - they imply that by filling all the water troughs the humidity should rise to 65-70%, but I have filled them all and am still only at 48%. From what I have read, this is fine for the first 18 days but it needs to be higher for lockdown. Is this a fault with the incubator or is there something I am missing? There are a few ventilation holes - would covering them help or be detrimental to the hatch? There is a large surface area of water - most of the base of the incubator is filled.

We live in an area of fairly high humidity - NZ in spring is pretty wet!

I have my eggs waiting to go in but don't want to screw it up.

Thanks
Aroha

 

[Ridgerunner]

What incubator do you have, make and model? Forced air or still air? That might help us a bit.

Have you checked your hygrometer to make sure it is working right? Thermometers and hygrometers are notorious for not working right and messing up hatches. You may need new instruments.

Rebel’s Thermometer Calibration
http://cmfarm.us/ThermometerCalibration.html

Rebel’s Hygrometer Calibration
http://cmfarm.us/HygrometerCalibration.html

During the first week or so it doesn’t matter, but after that the eggs need an exchange of air. The egg shells are porous and the chick inside is breathing so it needs to get rid of the bad air and get new good oxygen-filled air. The later in the incubation the more those vents need to be open. That’s more important in a still air than a forced air but I’d still want at least one vent open. Lack of oxygen is one reason some eggs can go to full term or even hatch and then die. They suffocate. The more vents are open the more humidity escapes.

The temperature and humidity of the air going in has a big effect on the humidity of the air inside the incubator. What environment is the incubator in? Is it inside an air conditioned house where you are wringing the moisture out of the air? Maybe you are heating with wood and the air is extremely dry? The incubator should not be in the draft created by a vent and the temperature should be pretty stable around it.

Don’t believe them when they start putting numbers to what humidity you should have with certain water reservoirs filled. You have to determine that for yourself. Just moving the incubator from one side of the room to another can make a big difference. I can have a difference of 15% in the humidity inside mine depending in the time of year and the conditions of the air going in. That’s with the incubator in the same place, temperatures stable, and no draft from vents.

In most incubators the way you control humidity is the surface area of the water. If your instruments are working properly then you can try adding more reservoirs in there somewhere. Or put sponges or towels in there with a corner in a reservoir so it will wick moisture out and give more area for water to evaporate. That will drain that reservoir faster so watch out that it doesn’t go dry. That’s the main purpose of my hygrometer. When humidity starts to drop it’s time to add more water.

Something else to check. Is your lid on correctly? One time the cord to my turner was not in the channel for it and it was cracking the lid open. That came close to driving me nuts trying to figure out why the humidity was so low.

Good luck!

 

[Aroha]

Thank you so much for your reply. I wonder if the hygrometer isn't working properly. It dropped to 44 over night. We have no heating on at the moment. The incubator is in the garage (behaved the same in the house yesterday), day temperature is about 20 oC and night temperature about 10 oC, it's rainy and the weather website says humidity is 75% - I assume the humidity in my garage will be lower than that, but it must still be quite humid.

When I take the lid off the incubator, the air inside is humid, much more so than the air outside. I will try that calibration method - the hygrometer is built into the lid so I'll try it with the whole lid in a plastic bag and hope it works. I could buy another hygrometer but if this one doesn't work, I'd rather it was replaced.

There is no brand on the incubator unfortunately - just says Egg Incubator on the box and the machine.