I am glad you decided to try and save the tadpoles. They really are important. You seem to be learning, you can culture more flies at home to save money and avoid trips. You just have to have the right media or food, wood wool (aka Excelsior) and the right containers. you can order this all from Josh's Frogs though the wood wool is cheaper at the craft store. I have to culture my own because I am allergic to the stuff in commercial media and I save money. I make cultures every 2 weeks from the boom of the last culture I made. You don't want to culture less often or you will have too few or too old flies and the culture will fail. Next time I make my media I will make a video of it to post on YouTube and share in a thread I started. I don't use potatoes in mine so it is not already on YouTube done by someone else.

Oh. one important thing. You will want to test one frog in each grow out tank for Chytrid fungus and Ranavirus before you release any into the wild. These diseases are killing wild populations and if your frogs have either they will have to be treated before being released. These disease can be food born so anything you feed them might give it to the whole tank.