The 70 gram.. I would have in a 6 qt tub until around 350 to 400 grams..... The 350 gram is fine in a 16 qt tub until around 700 gram range... Then a 32 qt is fine for a male fully grown.. female once they hit around 1800 gram range I move to the bigger size tub ... That's just me but I been wondering what other people do...