I have 5 new Black Australorp pullets. Just picked them up from the co-op today so I'm guessing they are days old. I have them in a tub with a 250w heat lamp, wood shavings, medicated chick start and water fortified with Sav-A-Chick. When do they start needing sun? Should they have a little bit of outside time during the day now? How can I ensure that they grow to be good layers?