First candling: 7 days After a week of incubation, place your egg onto your egg candler in a darkened room and turn on the light. You should be able to see shadows from inside the egg. With practice, you will identify fertile eggs by the dark dot, the embryo and the spider-like blood veins spreading out around the egg.
On day 7 of candling eggs, you should start to see the beginning stages of development of your chick embryo. If the embryo is developing, you will see a network of blood vessels running from side to side across the egg. Attached to the veins you might see a dark spot, which is the developing embryo.
The presence of branch-like structures indicates you likely have a partially incubated egg. If you can't see any defined shapes, it appears solid, or all you can see is an air cell, discard that egg because it's likely gone bad. Likewise, if cracks in the shell are visible when candling, trash it.
The best kept secret in determining an egg's freshness is to see if it sinks in water. To try the egg water test, simply fill a glass or bowl with cold water and submerge the eggs. If the eggs sink to the bottom and lay flat on their side, they're still fresh.
If chick embryos develop to the pipping stage, or at first shell cracking at hatching, they are normally healthy enough to hatch unless some incubator adjustment prevents it from happening. The problem is usually caused by either 1) poor ventilation or 2) improper humidity.
In candling, you'll be able to see your developing chick moving. Soon after that, you'll be able to see very little. As the chick grows and starts to fill more of the egg, candling becomes more difficult - the chick's body simply gets in the way.
If you see a blood ring inside the egg with no embryo, or a tiny embryo with no visible eye, this indicates that the embryo stopped developing in the first three days.
* During the last 3 days of a hatch, it is best to avoid candling the eggs unless you have a specific reason to. * A vague ring inside the egg and little or no veins. * After 10 days the egg is still clear.
And candling does not harm your eggs. Just as the mother would naturally leave the nest for a short time each day, you can safely take your incubating eggs out of the incubator for the few times you will be candling them.
You will see that supermarket eggs are infertile. Did you know you can determine if an egg is fertile or not by looking at the germ spot? The germ spot is the white spot on the yolk. The non-fertile germ spot contains only the female's cells and looks like a solid white spot.
Day 8. By the start of this week the embryo will be clearly visible when you candle the egg. The eye will become more prominent with time but even at this stage it can be clearly seen. Look for a large black dot.
If dirty eggs must be used for hatching, it is recommended that they be incubated in an incubator separate from the clean eggs. This will prevent contamination of clean eggs and chicks if the dirty eggs explode and during hatching.
To know if the egg is a winner look for a network of blood vessels that appear white. A dark outline at the center of the blood vessels is the embryo. You may even see the dark eyes of the embryo or the embryo moving slightly. These are both telltale signs that the egg is a winner.
Candling does not damage the embryos inside the egg, providing you maintain the temperature of the egg. Don't keep eggs out of the incubator unnecessarily, and don't overheat the egg if using an egg candler with a bulb. Modern LED versions do not give off heat and are a better option.
You'll see blood pumping through the heart of a tiny, developing embryo if you candle a fertile egg on Day 4. If the embryo dies at this point, you may still see a faint network of blood vessels inside the egg's contents. An embryo dying at this point will show a large, black eye.
Chicken eggs should hatch 21 days after they first start in an incubator. (Remember that your eggs have already been incubated for 14 days before you receive them!)
How long after pipping will my chicks hatch? Some will come out very quickly, using their egg tooth to "unzip" until they're able to wiggle themselves free within an hour or less. For others, progress can be very slow, sometimes taking more than 24 hours. It's a hard, tiring process for a tiny baby chick.
A "dead germ" can be distinguished by the presence of a blood ring around the embryo. This is caused by the movement of blood away from the embryo after death. If you are not sure whether the embryo is alive, place the egg back in the incubator and retest later.
Once the nest is “inactive”—that is, there are no viable eggs or live young—it is safe, and legal, to clean out a nest. We recommend disposing of those eggs, deceased young, and/or nest materials (e.g., if you're cleaning out a nest box) in a place where they won't attract insects to the nest area.
To perform the float test, place the egg in a large bowl of water. If it sinks or stays at the bottom, it is still fresh. An older egg will either stand on its end or float. The float test works because air builds up inside the egg as it ages, increasing its buoyancy.