I see a lot of Dumor and Purina being used, and was just wondering if I'm the only Blue Seal feeder on here... The Medicated Chick Starter states to put them on Grower-Cal at 8 weeks of age. But I see some people feed chick starter until 17 weeks (or maybe I misread?). So anyway, I should just follow the manufacturer's advice right? and start them at 8 weeks on the Grower-Cal?