You can move away from medicated feed at this age if that's what you're currently using. Continuing with a non medicated starter/grower is perfectly fine. In reality there is no need to ever switch excepting form of feed if you experience a lot of waste. We go to a pellet form all flock type feed once the chicks are around 12 weeks of age. Find that to be less waste of feed. For that we use Turkey/Gamebird finisher. Otherwise, with small chicks about we use non medicated starter/grower for entire flock. Toss oyster shell on ground once a week or have in side feeder for calcium supplement once the pullets come into lay.