How To Make A Homemade Egg Candler Using Common Household Materials

Candling Eggs

Found an old can light in the garage. I bought a flourescent bulb for it, since they don't make much heat.	Cut a hole in cardboard so the eggs would set slightly in it. I made two of these, one for the smaller bantam eggs.
Here it is with an egg on it.	Here it is with an egg on it -- lit up!

How to candle
To candle, darken the room. Eggs can be out of the incubator (or away from a broody hen) for up to 20-30 minutes before starting to cool down inside, so don't rush. You can GENTLY roll the egg on the candler to get the best view.

Out of the 14 eggs in this batch, we removed nine by day 14 that were obviously not developing. There is a chance that a non-developing egg will explode in the 'bator, and that is messy and STINKY. It hasn't happened to me yet, though.

I wouldn't candle after day 16 or 17. The eggs are mostly chick (black mass) and air sac by then anyway, and they should be left alone for the last few days before hatching (no turning from day 18-hatch).

Pics from day 8 candling
(click any pic to see a larger version)

Store-bought non-fertile egg for comparison	Undefined, hard to tell if there's a chick developing	Spots like this may indicate bacterial contamination
Nice air sac developing, a good sign Watch this one hatch	Nothing going on here!	This one had a faint ring, which is a sign of bacterial growth
This looks undefined, but ended up hatching out fine	Well-formed baby inside!	Another good one
good one	same one, slightly different angle	good one
something in there, for sure