Incubating leopard gecko eggs is a simple matter of collecting the eggs after they’re laid, putting them in an incubator at the correct temperature for the gender you’d like, and checking on them daily to see if the humidity is right and no mold is growing. After 35-90 days, the eggs will hatch.
In incubating leopard gecko eggs, you need to have the following things: substrate (it can be eco earth, perlite, or vermiculite), container, scale, water, and the incubator itself.
First, take your container, put it on the gram scale, and tare it so that the weight of the container is zero. Once you have done that, fill the container about halfway with the perlite. Once you have weighed the container with the perlite, you need to add the water which is 80% of the weight of the perlite. Multiply that weight by 1.8 so you’ll get the total way of the mixture. It is also recommended to put tiny holes on both sides of the container to keep the eggs breathe fresh air. If you don't want to weigh the water, you can simply squeeze the water and whatever is left in the substrate would be a good example of a good humidity rate. Not too humid or dry.
Once you have done all of this, add your Leopard Gecko eggs. Put the cover on and label the container. Write the date the eggs were laid, the names of the parents, and the most important part, the weight of the perlite and water.
Now put your eggs in the incubator. The sex of the geckos will be based on the incubation temperature. If it's a high temperature like 87-89°F, you'll probably get a male, roughly 25-40 days of incubation time. But if low temperatures like 80-83°F, mostly Females, roughly 65 days of incubation time. And if 84-86°F, will be mixed of males and females, roughly 55 days of incubation time. But always remember, the higher the temperature, the faster the eggs will hatch, and the lower the temperature, hatching will be a little bit late. Usually, it takes the first 2-3 weeks to have their gender fixed and after that, you can change the temperature to lower or higher.
The color of your leopard gecko sometimes also varies depending on the temperature. The higher the temperature, the brighter the color will be and the lower the temperature, the darker color your leopard gecko will be.
BUT, it is not really recommended to change the temperature too often because that is very risky and can kill the eggs. You can slowly rise up the temperature each week, for example just 1 Fahrenheit per week. If you ever thinking about changing the temperature, make sure to get multiple incubators to minimize the temperature fluctuation risk.