Uh, let me clarify that. 29/30 gallon would be the absolute minimum for 2 males. If you have a 50 I think you could easily do 3 probably 4. Just watch them reall close for the first week. the only problem I see you haveing, is if one gets more stressed than the others during transport. The others will see the weakness and kill him if left alone. Just make sure you get them all at the same time, if you get 3 and try to add a 4th later, he might not make it.