Hawkeye,
Others may disagree with me but I'm not the only one on the forum who has found that the tadpoles will not be a food source for your fish. I guess see what your observations are. I would work on other forage base food options and I agree with you, the ones where you pay a little to get the food chain started and the adults (crayfish, minnows, scuds, whatever) make thousands of their own future generations is the most economical plan. It pays a little up front to create the conditios, the refuge places, the structures that support the spawning and survival of those little forage critters.
CC
