This post was most recently updated on March 1st, 2020
Every Spring the urge for baby chicks kicks in! What is more exciting than incubating and hatching your own chicks?!
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I have built our own egg incubator for a fraction of what you can buy them for. DIY incubators are notorious for being a great idea, with low success rates, but if you have a source of free fertile eggs it could be worth a try!
Chicken eggs must be held at 37.5C (99.5F) and humidity should be 50-65% during incubation and 70-75% at hatching time.
It is very easy to overheat the eggs in still-air incubators and difficult to maintain proper humidity so I have installed a fan in our DIY incubator to keep the air moving.
It takes 21 days on average for an egg to hatch once incubation begins, 18 days of 60% humidity and turning at least 3 times per day, the last 3 days you want the humidity to be up closer to 70-75% and stop turning the eggs to allow the chicks to get into optimal hatching positions.
I have used a tray with an auto-turner, but you can manually turn them three times a day if you prefer.
Different types of DIY Incubators
There are several different ways to make your own incubator at home.
Here are a selection of other ways to make your incubator:
Double Cardboard Box Incubator – see below
How to make an incubator step by step for chicken eggs
An insulated box – double walled cardboard box, or two boxes that fit inside each other well
A smaller box to sit inside the larger one
A computer fan – I used a USB one
A light fitting
A 40 watt incandescent bulb
A thermometer and hydrometer
A cup or bowl for water
An egg tray and motor (optional)
You can buy most of these supplies from Amazon.
I had to attach a plug to the motor that came with the egg tray, I did this first and made sure it was working.
I attached some polystyrene to the bottom of the fan using double sided tape to keep it up off of the bottom of the box to increase the airflow.
I cut a hole in the side of the box to view the thermometer without totally opening the box up.
The next step is to poke holes in the box and tape on all the plugs, then re-cover all the holes to keep the heat in.
Inside the larger box I placed a smaller box. This will hold the egg tray up away from the light/heat, water and the fan.
On the end where the plugs go in, I sat a glass of water, the fan that is raised off the ground slightly, and the light bulb. On the other side I placed the thermometer, pointing out toward the specially cut window.
Then on top of the box I balanced the egg tray and motor, attaching it to the end of the box with a little piece of tying wire.
Once you run your DIY egg incubator for 24 hours you will have a better idea of how warm your box will sit at.
You may need to poke holes in the box to lower the humidity or reduce or increase the wattage of your bulb to help with the temperature, two other options are using a dimmer on the light and using a sponge with more or less surface area to adjust humidity.
Once you know you can run it for 24 hours and maintain temperature and humidity you should be ready to add some eggs.
The incubator should be placed in a location with the least possible fluctuation in temperature and humidity throughout the day—a basement is ideal, a sunny window is not.
The First Time we Used Our DIY Chicken Egg Incubator was a DISASTER
So despite me trialing the DIY egg incubator for 24 hours and it holding its temperature well during the trial, we had a disaster!
I moved the box into the laundry and set it up with the eggs and the auto-turner and all went well until I checked in on everyone in the morning to find
1) the temperature was only 35C (we are aiming for 36.5-38.5)
2) the auto-turner was not turning anything – the bolt that held it on to the egg tray thingy had worked its way loose and it was gyrating all by itself in the corner.
SO I covered the box in a warm blanket and walked off for 90 minutes. Then came disaster number 3) – now the box and the eggs were 49C!! ARRRGGG!
After trying and trying to cool the unit and the eggs down, I have had to poke many many holes into the box to drop the temperature and add in another wet rag to re-increase the humidity.
Now it is holding temperature and humidity beautifully. But I murdered my fertile eggs, so I had to add new ones.
I resorted to manually turning the new eggs 3-5 times a day.
- Don’t assume it will hold temp after just running for a day/few hours.
- Don’t rely on technology, sometimes it will let you down!
- Don’t cover the box in a blanket to help it heat up and then walk away.
- DIY egg incubators might not be very successful until you get it right
Making a Styrofoam Egg Incubator Plus improvements for a Cardboard Box Incubator
Our cardboard box incubator had a very poor hatch rate, so we decided to have another go and see if we could improve our temperature and humidity control.
The first thing I did was make my own “water-wriggler” because I am cheap and impatient and didn’t want to buy one.
It is basically a snap-lock bag half filled with water then placed inside of another then taped into a cylinder. In the middle of the water tube I have placed the end of my cheese making thermometer.
This will give me a better idea of the temperature actually inside the liquid of the egg.
Inside the incubator box I filled two pickle jars with warm water in the box that sits next to the computer fan and light bulb and under my new styrofoam box. These will act as a heat sink and help stabilize the temperature.
To let the heat and fresh air into the styrofoam box I cut two 1 inch holes on the end where the light bulb and the fan are. I also poked a 1 cm square hole on the opposite end to put the thermometer into the water tube through.
I was struggling using a 60W lamp, it was too hot so I had to have lots of holes in the box to let the heat out, so that also let all the humidity out.
So in my 2.0 version I have reduced down to a 40W light bulb and taped over the holes in the outside box.
I cut a hole in the top of they styrofoam box and covered it with the front of an old CD case, and taped it down well. This gives me a window to check the temperature/humidity on my thermometer through.
I have also added a glass jar of water into the top box as a second heat sink.
I have found that two sets of two sponges keeps the humidity up, and I have to cover the box at night to keep it warm enough.
I ran the box for a full 48 hours to ensure I could keep the temperature and humidity stable before I added our new batch of eggs.
I poked the thermometer through to the water tube from the outside:
I have given up on our auto-turner for now, I am checking their temperature so often anyway (paranoid much?) So I may as well turn them while I am there.
The styrofoam definitely provided better insulation, and covering the boxes at night helped a lot. If I had kept the egg incubator in the living room where it is warm 24/7 we probably wouldn’t have this issue. But our laundry is on the cold side of the house.
Excitingly these DIY egg incubators did eventually work! We hatched out some very cute fluffy little chicks 21 days later!
We were having trouble keeping the temperature stable, with the eggs closer to the heater dying of too much heat, and the ones on the other side were too cold to develop.
To remedy this, we added a folded towel over the top of the whole incubator, and this had wonderful success!
Update: We ended up giving up on our home made egg incubator and bought a basic 24 egg incubator. We have had much greater success with it.