tadpole care?

[Charlotte Benedict]

I have found a fountain with a lot of little black tadpoles, not even 1/2 an inch long. I wanted to catch some and raise them in a ten-gallon tank. I bought an in-tank Tetra filter for a twenty gallon. Will that work? Also they didn't have any tadpole food, so I grabbed some algae wafers. Will they eat them? Or are they carnivorous? Any help would be appreciated!