I have 4 Wyandotte pullets, 2 are 22 weeks old and 2 are 16 weeks old. None are laying yet. They have nearly finished their bag of medicated grower pellets that I have had since I got the older 2 at 12 weeks old. I have read that you should switch to layer pellets when they are about 18 weeks old (or point of lay?). However, I have kept feeding them the grower pellets due to the 2 younger ones still needing the grower pellets and the fact that the older 2 hadn't started laying yet. I'm looking for advice as to whether it would be better to buy them a bag of layer pellets now, or if the extra calcium would be bad for the 16 week old ones? In which case would it be better buy another bag of grower pellets (non medicated this time) and just start providing shell grit once the older ones actually start laying?