>>Most of my tadpoles now have back legs. Yea!
>>
>>When do I need to change their food FROM a primarily veggie diet?
>>
>>And what are some good foods to go with. So far I've been giving them algae wafers and seaweed sheets. They only eat things that are on the bottom of the tank -- they ignore any floating foods I try to give them.
>>

You can always add a small piece of raw beef with calcium powder sprinkled on it to the tank. They will nibble on it and in the process also obtain some calcium supplement. Make sure the meat does not pollute the water too much by removing it before it starts to decay.