You're in Florida. What's your weather like right now? Thought everyone out East was suffering with a heat wave. If that's so, maybe only give them the brooder heat/light when you see them crowding together like they're chilled. As a dietary boost, you could add a couple of droppers full of Polyvisol vitamins to their water and 1 tsp. of apple cider vinegar to a gallon. If I suspect a chick or chicks are not eating, I will made a soft mush of their crumbles with some warm water. Most chicks really love that wet mush.