even when your knife is fully grown it will be extremly slender and it's lateral height will be small. You're looking at a cat that both parent species can get to 6ft. in the wild. As stated before mine is at 28 1/2 inches at less than 2 years of age. Go for a minimum footprint on your tank of 4ft. x 10ft. even then just pray he never gets more than 4 ft. not sure anyone has ever raise one completely as they seem to be a relatively new hybrid. In the catfish forum at the top the post catfish sticky i have some info on them. Expect with proper feeding and housing they will outgrow either parent fish. I wouldn't be suprised if they hit 5 ft and 100+lbs. in their lifetime. With that said some hybrids grow to more than double the parent species size like ligers for instance. largest tigers are around 600-700lbs. and largest lions are around 500-600lbs. the liger is a hybrid of the two and can reach wieghts of over 1200 lbs. so who knows what we have on our hands. They might get to 200 lbs. in aquariums. We just dont' know till someone has had one in proper conditions for 20 + years.
