moved to hybrids section for you
personally, I like a medium to slightly large hump but there is definitely a such a thing as too big. if it extends outward past the snout of the fish, that's when it is too large, imo. here are a couple pics of my newest red devil. this first pic was taken right after I got him in mid-
February.
and here is a more recent pic
a lot of things can affect the size of the nuchal hump. genetics will play the biggest part. many flowerhorns are specifically bred for large nuchal humps. if the fish has a defined territory and another fish to show dominance over then the hump will usually grow larger. for instance, if you have 2 males in the same tank with a divider (like I have my red devil setup in now) then the humps will grow larger. once I put the divider in the tank and another male on the other side, his hump got bigger, but then it got bigger still when I put a clay pot in there for him to claim as a territory. diet also plays a role...some foods will encourage hump growth. I was told that Hikari Oranda Gold and possibly even Hikari Lion Head formula will encourage hump growth.