We bought 6 ISA Browns just before Easter. We are getting 3 eggs the in same 2 hour window every day. Always 2 dark and 1 light brown egg. They have been laying for about 2 weeks now. We were wondering how long before they are all laying. They are all the same age about 20 weeks old. They are fed 16% layer pellets. They get a few pieces of watermelon or a cold ear of corn as a treat but mainly the layer pellets. They sure are fun to have around.