Look at the glow from your heat lap its almost completely fills each side of the brooder. My guess is its to hot for the chicks in that brooder. Check the heat on each side of your brooder. Then you need to give them a much cooler area to go with a warm area so they can get away from the heat if they need to. Get some electrolytes in the place of water see if that helps. There is a home made electrolyte formula that you can make from items in your kitchen. Don't give chicks any water or liquid that is cold. You want it at room temp before giving it to them. Here is the recipe I use for my own chicks. 2 quarts of water, 1 teaspoon of salt, 1 tablespoon of Sugar, 1 teaspoon of baking soda. I place all this in a small pot put it on my stove and heat it till sugar is dissolved. I let cool and give to my chicks changing the water each day. I double my recipe and refrigerate what is left over. I remove a cup of the liquid and sit on the counter to warm up each morning. The electrolytes will last for a week in the frig.