Oh yeah, I do start all my chicks out with the electrolytes and probiotic. I usually alternate days with it myself and I also start them out on the medicated chick food. I'm not exactly sure there is an exact science to it but make sure you also have fresh water for them as well (so I've read).
Unfortunately the little one didn't make it. I guess it was bound to happen at some point. Out of 36 chick's, this one was the first one I've lost. I've read that sometimes you can do everything to help a chick survive but still usually never end up making it within the flock. Still doesn't make me feel better about it though
So sorry about your loss and these things will and do happen
