I'm not exaggerating buddy, a 24" fish WILL NOT live a happy life in a 75g, that's if it even grows to its full size anyway! Just because a fish is "still eating" to quote, does not mean it is happy. There is a large difference between surviving and thriving, I don't think you really know the difference which is a shame. If you actually take some of this helpful info on board rather then blocking your ears to what you don't want to hear then you would realise you are not doing good for your fish and would consider selling him or upgrading. I'm not grilling you or anything of the like, just providing some helpful info that will greatly improve the longevity and health of the fish.