How do I clean a pot after boiling eggs? After boiling 8 batches of eggs, how can I clean the build up of calcium off the bottom of the pot?
Put some water in the pot
Add vinegar or citric acid (whatever you can get your hands on more easily). (Sorry, I have no measurements, I always eyeball it. I guess up to 5% for vinegar is fine, or one or two teaspoons of citric acid depending on the pot-size...)  
Heat to a rolling boil... (do NOT put your head over the pot to see it it works, especially when using vinegar)
After it has boiled for a minute, turn off the heat and let things cool down.  
Rinse the pot
Enjoy the (hopefully) shiny pot :)