When do I start blending layer food...?

[Catalina]

My girls will be 18weeks old in four days and I have 20 lbs of chick crumbles left.
Should I buy layer crumbles and start blending it into my chick crumbles?
They aren't laying yet and my local feed store only sells 50lb bags of feed.

 

[speckledhen]

You can either just finish your bag and start them on layer or go ahead and get some layer and start mixing it in now or when you get close to the end of your 20 lb of starter. At their age, it won't hurt them. Just don't give them oyster shell till they're actually laying.

 

[Catalina]

OK! Thanks!