There are feed stores and TSC’s in most areas. Just get the Corid if you are seeing blood. It is safe, even if it is not coccidiosis, but if they start to go downhill, it will delay treatment. Sometimes normal intestinal shed will be passed in the droppings, but with baby chicks, at that age I would treat them. The most common and serious time for coccidiosis is from 3 to 6 weeks, but they can get it later as well. Dosage is 2 tsp of the liquid or 1.5 tsp of the powder per gallon of water. Mix new each day. Treat for 5-7 days. Pictures of droppings are welcome here.