I read a ratio of 1:1 was being used, helps to start that way & adjust as you go. Finishing up Chick Starter; started end of Oct 2015; think I got few more days of feed (CS) left. Got 2RIRs & 2EEs @ 2wks, they're now 16wks and I love the benefits of FF - no feed waste, less poop, firmer poop & less stinky. I was told to put them on Multi Purpose, since they're short of being 18wks, supplementing with Oyster Shells when they're 18wks until the bag is done, then switch to Egg Maker. I was hoping the CS would last until they made 18wks

Know I'm short "only" a week but have read NOT start EM until they're 18wks. (just 2 wks away).
Am I on the right track or should I switch them to Egg Maker when I run out to the Chick Starter which will probably be this weekend?