I have 4 females and 1 male that are 4 weeks old. They've been eating nutrena nature wise starter. The bag is almost empty and ill be getting them a new bag this week. (Probably tomorrow). I was thinking I'd get the nutrena all flock? And they've been getting sand as grit. Should I change that? My girls won't be laying for a few months but when they do will I HAVE to give them layer feed or can they still eat the all flock and have oyster shell grit? And if they do have to have layer feed is that safe for my drake?