My chicks are 5 weeks old and have been outside with no heat for about a week. They're happy and healthy and always hungry, of course! I have them on 20% starter/grower mash. The label suggests that layer chicks should eat this to 6 weeks of age. I also give them greens in the form of thin clumps of soil with grass growing on it. My questions; 1) Should I switch them to 18% starter mash or can I finish up the 20% first? At the rate they're eating that would take up to about 9 weeks. 2) Are they getting enough grit with the soil? They tear it apart when they're pulling the grass up.