duck egg shells not forming

[Leeroy8736]

i bought 2 female pekins last march at TSC and im brand new to animals that actually survive in our care much less this far...haha...much less raising any kind of birds.theyre about 4 1/2 months old give or take and just started laying eggs yesterday like crazy ! im pretty excited but ive gotten 4 eggs in the last 24 hours about the size of of a grade A large chicken egg and only 1/4 had a completely formed shells.i use purina poultry feed layena crumbles and im aware of the need for oyster shell.the folks at TSC said its all i need even if my birds dont range.they do have access to a 4'x10' patch of ground and i see them digging with their bills often so i dont think grit is a problem either way but i could be wrong.

my question is if thats normal for ducks at this age ?

 

[chickens really]

First eggs can be that way till their egg making machine works all the kinks out....

 

[Leeroy8736]

thanks.ill let yawl know when it stops.i guess i have found about 10-12 eggs in the last couple weeks and so far only 4 keepers.