If you want, I can contact some much more experienced members of this Forum to help you out.

By 'tad food', do you mean the "Frog pellets" you see at petstores. If so, I recommend feeding them boiled, finely chopped, and finally frozen pieces of lettuce, as well as thawed bloodworms. "Frog pellets" are very low in nutrition, and I always recommend variety in the diet of any frog.

We will also need photos to identify the species of frog/toad, as well as confirm whether the ailment is Red leg.

Separating the sick tadpole from the healthy tadpoles should be the first thing you do. We don't want the virus/ailment spreading to the others.

Keep us posted. We'll help you as much as we can.