How long do chicks take to hatch after the first one hatches?

[The hen breeder]

Hi there, I've just had my first egg hatch out of 20 in past hour, A couple of others have pipped and I can hear chirping etc... How long will it take for all of them to have hatched- and should I remove the new chick?
Thanks

 

[hwd2002]

it should take up to two days.

 

[The hen breeder]

Okay, and should I get the other chick out or leave it in there?