Don't nerf Fizz's attack range, nerf something else
I totally understand that Fizz is too strong right now, and yes you should nerf the cooldown on his E, and remove some power, in the form of damage perhaps if he's too overbearing. But the 175 attack range is not only key to playing Fizz in lane where he can barely scrap any CS, but it's also thematic to Fizz's TRIDENT. Don't nerf Fizz in obscure ways that make him less fun to play, nerf him in another direction such as damage.