Nevertheless, Terramycin is an antibiotic, albeit, a mild one, and the amprolium that is in most medicated chick starters is not-it is a thiamine-blocker. No withdrawal time needed, even if they start laying while on that, but not so with Terramycin. I have brooded several batches of chicks and never put anything in their water except a tiny bit of organic apple cider vinegar. No sugar, nothing. If you start Terramycin, you will immediately start building immunity to antibiotics from day one. Dissolve a bit of sugar in the water for a day or so after shipping, but no longer. They can develop diarrhea if consuming too much of that.
Everyone can do whatever they want, but they should know what they are giving the chicks and what the potential problems are.