my freind has a 75 gallon hospital tank, becuase i has 3 100+ gal tank, and a 350 gal so they will go to the 75 gal, we just dident know what kind of catfish they were, they were given to me as a gift, thats good to know though but i had a idea they would get really big, but i knew about the birchir, he is about 6-7 inches right now, hoppfully i will be getting a 120 gal tank for them in the near future hopfully by the end of august