We currently have a few duck eggs and chicken eggs in the incubator. No this is not an expensive (we picked it up from EBay for a little over $60)and yes we do turn the eggs manually. However we have successfully hatched 2 rounds of chickens, so since our ducks have started to lay, we’re attempting them too.
So I thought I’d just take a few pics of the ‘candling process’. Essentially after approximately a week (for chicken or in this case duck eggs) we take a small (hand sized) LED torch, place it close to the egg shell, in a darkened room (or corner) and you can clearly see the actively inside.
Now anon-fertilised egg will remain distinctly fluid and you will be able to identify the yolk, it will bob to the top of the egg as it is turn. We remove these (allowing more room for the eventual hatching chicks/ducklings).
In these pictures (although their not great quality- I’ll try and get better ones next time) you can clearly see a solid form developing, and veins. These eggs have been fertilised and are growing little birds!
Place these back in as soon as possible and replace the lid, as they need to be kept at a consistent temperature and humidity. Too long out of the incubator could destroy their development.