I raise Bullfrog tadpoles every year. I just drop them into one of my established tanks. Be extremely careful when moving them as they are easy to injure internally, and do not put them in a tank with fish that may nip at them. They prefer lots of plants to hide under and an established tank with algae to munch on. Once they start absorbing their tail they will stop eating. After they are done metamorphosing they need to be removed quickly or they will eat any small fish you may have or starve to death. You'll know when it's time to take them out because they'll try to get out of the water or always hang out at the top of the tank.
When you remove them, you can release them into an area where they are found naturally or build a terrarium/vivarium to house them. Never release non-native species as frogs can be extremely invasive and destroy an ecosystem. The specifications for a terrarium/vivarium will depend on the species of frog.
Last edited by Indychus; 04-28-2013 at 02:19 PM.
Reason: Added info