Most of so called fw puffers are born upstream in rivers and slowly migrate to brackish mangroves, then as they get larger eventally to open ocean(full salt) with some exceptions. Ive drip acclimated many green spot, jade, and figure eight puffers to full salt 1.025 within a 6-8 hour period from full freshwater(takes patience and skill though). Didnt cut life in half, they actually seemed happier and still thriving. Black mollys perfer brakckish and many guppies and mosquito fish do also. as to orbit that is not a smart way to acclimated the fish at all, going from fresh to salt in an instant is like being shot from the top of mount everest down to the bottom in a second. It stresses the fish out bad. you have to slowly adjust them to it by drip acclimating SLOWLY. Thats why his fish lives were cut in half.