I have 6 hens, 1 is laying with an egg a day! And, we have 5 more NOT laying, yet! We just finished the bag of Chick-Starter Crumbles, and want to know if I should buy more Chick Starter or move them onto Laying mash!?!?! They are ALL are 18 weeks old! I have heard they should not have laying mash until 20 weeks! Going to the feed store tomorrow! What , should I do?