I raised about 50 whites tadpoles into frogs last december, with only 3 deaths (it happens).
I split them up into groups, and I noticed EXTREME differences in growth rates... From what I gathered they love the warmth and thrive where they can get a little sunlight. They also appeared to grow better in a crowded environment but I would suggest you give them plenty of space to swim.
I kept them in rain water which I replaced every few days and fed them boiled lettuce (which was then cooled before I fed them lol) and fish food (good for protein). When they get larger they will also eat bugs or any other dead organic matter they find (including their deceased brothers & sisters).
Make sure you keep them in a well ventilated area, and don’t “kill them with kindness” lol, they are tough little fellas. If you have any questions don't hesitate to let me know
Goodluck!