When to lockdown for silkies?

[hd_darcy]

I have 4 silkie eggs in my Brinsea from shipped eggs (along with 2 of my own mixed cochin bantams). When should I start lockdown? I have read to start lockdown one day early with silkies? Or best to wait? Also when I candled it appeared that one of the air cells was opposite of the others on where it should be. Is that normal? Anything I should do with that particular egg?

Thank you for any and all help!

 

[hd_darcy]

Anybody?

 

[Suzie]

My Silkie's have always hatched on day 21....same as a normal chickens.....hope that helps!