Please note : This is a long page because it has many descriptive pictures. However it's important that you read it all in order to make sure you take care of everything for lockdown and have a successful hatch.
"Lockdown" is simply the word used to describe the time when an egg
incubator has its settings optimised ready for hatch. The
eggs are not turned or candled again and the incubator is left with its lid
closed until after the chicks have hatched.
It requires five main things to be done.
The generally agreed time is three days before the eggs are due
to hatch. For normal sized chicken eggs this is at the end of Day 18 of
Bantam eggs can sometimes hatch more quickly, at around 18 or 19 days into incubation (although it’s not always the case) so should be locked down at around day 16.
If you have an incubator with both large and bantam eggs and you don’t have a separate hatcher, it’s fine to lock down all the eggs at Day 16.
There are just five simple things to be done on day 18 to lock down your incubator and make sure you have the best possible chance of healthy chicks hatching.
You need to prepare a non-slip surface for the hatchlings when they appear.
Chicks will start to move around immediately after hatching - they stumble around the incubator, into and over other eggs, into and over each other. A slippery surface can cause their weak, spindly little legs to do the ‘splits’, resulting in a condition known as ‘splayed leg'.
Splayed leg can be fixed, but it’s better to prevent it from happening in the first place.
So, choose a non-slippery surface - I use a plasticised material usually used for shelf lining ('antiscivolo' meaning anti-slip - for those who don't know, I live in Italy!).
It's available from Amazon - and in a range of pretty colours! (This is an "affiliate link", which means that if you click and buy something, I earn a small commission at no extra cost to you).
your eggs out of the incubator and put them somewhere safe - they’ll be
fine for a few minutes. I use a towel on my incubation table to place
Now remove the turning plate or egg tray - in the case of this incubator it's the yellow disc with the holes where the eggs have been.
Put the disc or egg tray on top of the plastic and draw around its circumference with a pen.
Now cut out to the shape of the tray, making it slightly smaller than the tray itself.
For Brinsea's small incubators, fold the material into quarters and cut out a hole in the middle to allow for the water pot.
That’s it! You should now have a chick-slip-proof mat to keep your chicks safe when they hatch.
I make exactly the same type of base for chicks hatching in my Brinsea Octagon 20 incubator.
Hatching can be a messy process, so once all the eggs have hatched it's wise to discard this base and make a fresh one next time you incubate.
Before you put your eggs back into the incubator, candle all of them in turn.
Eggs which have shown no signs of development should be removed at this point. This is an example of an egg which is clearly not going to develop.
Eggs with cracks which also have ‘gunk’ on the shell - a kind of sticky
oozing liquid - should also be discarded straight away. These eggs have
stopped developing and if left will explode, scattering bacteria over
the rest of the hatch.
Eggs with a "blood ring” should also be discarded. A “blood ring” is a sign that the embryo has died and the blood, which in a healthy hatching egg is spread by a complex system of veins, has collected in one place. This is an example of what to look for in this type of egg.
For more information and an explainer video about how to spot a blood ring, see this page.
You will hopefully have been doing this throughout incubation as you
candle your eggs but it’s important especially to do it at lockdown.
This is where the chick should begin to break through the shell. It won’t be exact because the air cell will continue to grow larger over the next three days, but it gives a reasonable picture.
If your chick begins to ‘pip’ elsewhere it’s a sign that it may need some help.
Eggs which are showing ‘normal' development for Day 18 - i.e. most of the egg is dark, with a growing air cell - can be replaced in the incubator. Do not place the turning disc back into the incubator - the eggs should be placed lengthways on your non-slip base.
For incubators like the Octagon 20, which hold eggs standing on end, this is the time to lay them flat. I can generally fit around 20 - 22 standard sized chicken eggs in this way - but it does get very crowded once they start to hatch!
Humidity levels for hatch need to be higher than for incubation, so at lockdown we need to adjust them accordingly.
The membrane which surrounds the chick must be kept moist enough for
the chick to be able to peck through. If it’s too dry, the chick will
get stuck and won’t be able to hatch.
If you are using a humidity pump with an incubator like the Octagon 20, the percentage should be increased now until the digital readout reaches 65%.
If you’re using an incubator like the Mini Advance which has neither a humidity pump nor a percentage readout, you need to rely on the manufacturer’s instructions.
In the case of the Mini Advance (or any of Brinsea’s small incubators) both chambers of the water pot in the centre of the incubator should be filled at lockdown and kept filled right through hatching.
Make sure you put the guard on the top of the pot - newly hatched chicks can easily fall into it and drown.
Once chicks get to this advanced stage they need a much higher supply of oxygen than has been the case before now. Poor ventilation can lead to chicks dying even at this late point.
Make sure, whichever incubator you’re using, that it’s standing in a place with a good supply of air - not shut in a cupboard, for example.
Smaller incubators with a fan, like the Mini Advance, will take care of ventilation for you so there’s no need to worry.
you’re using an incubator with an air vent (the Octagon 20, for
example), open it to at least halfway at lockdown.
You may need to increase moisture levels to keep humidity at the right point - before I had the humidity pump to take care of this for me (what a lifesaver!) I used wet kitchen towel for this if necessary.
The chicks now need a bit of peace and quiet to get themselves into the
right position for hatching, so you should stop turning the eggs now.
If you’re using the Mini Advance, the incubator will automatically know when this should happen and will stop turning for you. All you need to do is remove the turning disc and substitute your plastic flooring.
If you have an incubator like the Brinsea Octagon Advance which uses a turning cradle, simply lift the incubator off the cradle and place it on a flat surface. You can now unplug the cradle, clean it and put it away for next time.
From now until hatching, your incubator lid should be opened as little as possible and the eggs should not be touched or candled again.
important that humidity levels are maintained inside the incubator throughout lockdown and hatch so
that the chick does not get “shrink-wrapped”. This happens when the
membrane dries out and literally shrinks around the chick. The chick
can’t move and so can’t hatch.
Opening the lid will drop humidity levels massively which is why it needs to be avoided as much as possible from now on.
Brinsea's Octagon 20 incubator's air vent on the front of the machine helps control humidity without disturbing the eggs. To increase humidity, close the vent to the three-quarters point. Do not close it completely - the chicks need oxygen from this point onwards.
To decrease humidity, open the vent fully as in the picture below. Wait until humidity has stabilised and then close the slider to the halfway point.
When I first needed to do this after lockdown I was terrified, because all the advice is not to open the incubator at all after day 18.
But how to fill the water chambers if we can’t lift the lid?
I’ve since learned to relax. Opening the lid occasionally for a few seconds to fill the pot won’t affect humidity much, and the levels will rise again, although that can take a while.
One word of warning though : do avoid opening the lid if any egg has started to ‘pip’ - that is if you can see even a tiny hole or crack. A drop in humidity at that point can be fatal because the internal membrane can dry out in seconds and as it does so, it wraps the chicken too tightly for it to move.
These links will take you to pages which are designed specially to help you through the process. The first is a link to my free, 28-day, step-by-step hatching series - you're very welcome to join in!
Click on any of these pictures to go to the page.