Baby chicks dying!
I would give them plain water (and take them off the medicated food once you use what you have left)...sometimes all the "precautions" people recommend on boards like this are counter-productive. I don't know for sure why you are losing babies, but maybe it's just failure to thrive. It is a shame to lose little ones, sorry you are having such horrible luck
Not sure what your ambient temps are but heat stress can do a quick number on the chicks when real small. A buddy of mine lost 4 or 5 yesterday when the temp climbed into the mid 80's in the afternoon. When he realized it he got them out of the brooder and out in the open (with a retainer fence and a cover over the top). Let's them separate and lay around on the grass. Put a big waterer in with them. After a couple of hours they started looking much better -- except for a few.