What they need is food, water, protection from predators, and protection from the elements. Sounds like you have that covered.
Your feed needs to be age appropriate. That means the amount of calcium and protein needs to match their age. That information should be on the label.
The calcium needs to be in the range of 1%. It can be a little below or a little above, just somewhere in that range. That gives them enough calcium for good bone growth and for other body functions without giving them so much that it harms their internal organs. Any chick feed should be fine. What you are trying to avoid is the 4% calcium in Layer feeds.
You have latitude in the protein. We all have our opinions but at 9 weeks I’d be fine with anything between 15% and 20%. Generally a 16% protein Grower is recommended on the bag for chicks that age, but many people use feeds with a little more protein and they do fine.
The scratch should be fairly limited, no more than 10% of their daily feed. The Chick Feed is a balanced diet, giving them everything they need to grow strong and healthy. Scratch and other treats are not balanced so they should be fed in moderation. A general rule of thumb is that they should be able to clean up everything that is not their basic feed in about 10 to 15 minutes so their diet stays balanced.
The form of the feed is irrelevant. The way it is made, the manufacturers collect everything in their formula and grind it to a powder. That is called mash. Mash is normally served damp, as in a paste. The ingredients can separate out and the chickens will not necessarily get a balanced diet, but by making a paste while the ingredients are still mixed you overcome that problem.
To make pellets, they wet the mash into a paste, squeeze it through a die, and flash dry it. They just break them off as they reach the right length. To make crumbles, they gently crush the pellets to the right size. Since these are both made from that paste then dried, the ingredients are thoroughly mixed and held in place. Even if some return to the powder state, they are still going to be a balanced diet.
The reason they make the different forms of feed is that different automatic feeding systems are made to handle each of these forms. Different feeders can better handle different forms of the feed. I personally like the pellets myself. I do not have automatic feeders but with my feeder type I think I get less waste with pellets.
Baby chicks cannot handle the pellets, they are just too big, but they can handle mash or crumbles. I have had to grind down the crumbles a bit the first week or so with some chicks because some of the pieces are still too big, but they soon can handle those. At nine weeks yours should be able to handle pellets if you can find that form in the right percentage calcium and protein you need, but most pellets are likely to be for laying hens with too high a calcium. Crumbles may be your only realistic option.
