I have 9 brown layers and 2 of them are just starting to lay, they're about 21 weeks. They're only laying every 4 days but the nights are coming early and I've just started lights. We finally had enough eggs to make our first family scramble and we noticed that when cracking the eggs they were very strong. I only started giving them oyster shells today. should I continue to give them oyster shells or not? Is is a bad thing to have tough egg shells? I've read lots here about hens first eggs being soft shelled or not shelled.... definitely not a problem here. I'm new to the whole chicken thing and just want to be sure it's safe to give them the oyster shell. thanks