I remember when my magnificent was only 2-2.5 inches…
Almost 3 years later and he’s a beast at 6.5 inches and much slower in growth. I doubt he’ll ever get 8+ inches, 7.5 at a max. I will also say this is in a 4’ tank and not as active as foxfaces are said to be (I’ve never seen a foxface that was highly active, instead all the ones I’ve cared for swam for a bit then just hovered and repeated that). Mine is on the skinnier side and not extremely obese however I personally dislike having the overly obese fish and prefer the more natural bodied fish so I don’t really feed as much as some others do (I generally feed algae 2x a week and 1 heavily nutritional feed every day).