You can start at any age, a lot of people put their day olds on it. My FIL made me a special feeder, 4" pipe cut in half with little feet. I feed mine once a day, around 3pm, that way they forage all day and then eat what they want. I only feed FF, but some people also leave free feed crumbles or pellets.
I've been fermenting pellets with some scratch, but to up the protein I just stopped using scratch and added some calf manna. The FF allows more of the nutrients to be absorbed by the bird, and the waste has gone to zero, since it's wet and they can't fling it all over. A 50 lb bag lasts me almost twice as long now. It's a pain in butt during winter, since I have to keep the buckets I'm the house and take them back and forth to the barn, but they were freezing out there. Every time I think about quitting with it, I change my mind, it's worth the trouble.
I've been fermenting pellets with some scratch, but to up the protein I just stopped using scratch and added some calf manna. The FF allows more of the nutrients to be absorbed by the bird, and the waste has gone to zero, since it's wet and they can't fling it all over. A 50 lb bag lasts me almost twice as long now. It's a pain in butt during winter, since I have to keep the buckets I'm the house and take them back and forth to the barn, but they were freezing out there. Every time I think about quitting with it, I change my mind, it's worth the trouble.