Chicken laying egg without hard shell

[BFChicks]

I have ten 7 month old chickens. One or two of them are regularly laying eggs without the hard shell. The eggs just have in inner membrane holding them together. All of the chickens are eating the same feed- an organic feed from Purina along with oyster shells. I originally thought that this was from new chickens laying their first eggs and that the issue would go away. But two chickens continue to lay these eggs after more than 3 weeks. And they are laying these eggs during the night while they are on the roost sometime before 5 am. I find the eggs on the coop floor, sometimes they break open. I have to clean them up before the chickens get off their roosts. I think I have finally identified the two chickens who are doing this. Any ideas about the cause and if there is a cure for this?

 

[Kiki]

Is the feed a pellet or crumble or whole grain type feed?
What treats do you feed?

 

[BFChicks]

Is the feed a pellet or crumble or whole grain type feed?
What treats do you feed?

I am feeding DuMor 16% organic Layer Crumble. It states that is contains between 4 - 5% calcium. I also treat using dried mealworms, and seasonal vegetables/fruits in small quantities.

 

[Kiki]

I am feeding DuMor 16% organic Layer Crumble. It states that is contains between 4 - 5% calcium. I also treat using dried mealworms, and seasonal vegetables/fruits in small quantities.

I would stop the mealworms and other stuff today.
Don't feed any treats for a week or two and see if the problem corrects itself.

 

[BFChicks]

Thank you for the quick reply. I will try that.