Everyone has a thought about grit.
I am solidly in the camp that chicks should be provided Chick Grit. It goes in my brooder free choice when chicks are hatched. Even at less than 12hrs old a chick will select a piece or 2.
Anytime that you are going to give them something to eat besides commercial chick starter (crumbles) they need grit. It promotes gizzard function and helps process foods.
Hydro-Hen...that is Electrolytes, Probiotics and Acidifiers. Instructions are that fresh plain water needs to be available at least 12hrs a day as well. Personally, I would give them fresh water daily. Vitamins/Electrolytes once a week or better yet, for the first week, just give them a direct dose of 2-3 drops of Poultry Nutri-Drench per day.
My 2¢