For starters, I am brand new to this forum and far from an expert on fish keeping, but i would not consider myself a beginner. As i browse the threads i see so many responses saying "Your tank is way too small for that fish because it will grow to be (insert length here)...!" This is a really common response even when its completely off topic. I'm a little confused and surprised to see so much emphasis placed on the eventual size of the fish. Now, I havent had fish in years, and man things have changed in this hobby!! Mostly good things, but maybe not this IMO.Before ya flame me, let me explain. When i was a kid my dad was an avid Aquarist and wouldnt be satisfied owning the same tank with the same fish for too long. His crown jewel was always an Arowana which was occasionally traded in for a bigger one as soon as he could get a bigger/better tank. Its tank mates were traded in pretty often. Sometimes they didnt do well together or dad just wanted a change. Either way, he never said no to a species he liked because of its EVENTUAL size, he simply wouldnt plan to keep the fish for its entire life span. He often talked about appropriate husbandry but only in terms of how long he could keep the fish if it was too large a species. It was a very different ideal than i see here, where the focus seems to be "the tank has to match the species" no matter how big the fish is at the moment. I just cant imagine him 'tsk-tsk'ing" someone for having a 2 inch bala shark in a 30 gallon tank just because it will grow to a foot long...because thats a long way off...isnt it? I certainly wouldnt consider my dad an irresponsible aquarist but I wonder if most people nowadays would dissagree?? I'm really curious what y'all have to say because its kind of a big deal around here but i've never seen a real discussion about it.