Just noticed the age of your chicks, might be having a problem with Coccidiosis which Corid will turn that around ONLY if you are extremely diligent by isolating the youngsters. We had a short lived outbreak of that darn stuff during a very wet spring. So young chicks less than 16-18 weeks old, are easily affected by too wet of an environment combined with their food and droppings is the recipe for disaster. We lost three chicks in a row and then saved four more out of that same population. It took ALOT of diligence to save them, round the clock drops of ProMoxil, Corid, and B Complex vitamins. Even had to use two direct undiluted drops of Corid once a day for one chick via syringes straight into their beaks. But hey, the last four lived and are doing extremely well.