In my classroom we are raising tadpoles. One of them hasn't been growing very well. It is smaller than the others. It is in a separate tank than the others. No frogs are in this tank. Does anyone have any experience in raising the tads? How to feed them? Water changes?

The eh instructions I have for raising them is from "grow a frog". The food sent with them looks a bit like dirt. I haven't had much luck getting the tads to mature with this. Someone said to make a soup of goldfish flake powder and feed that to them. Other ideas, on how to care for and help sickly tads?