i did get rid of the ID sharks. even though they are only 4" or so right now i know they can get huge. i know the ideally that's what i should do with the bala sharks too, but i just love them so much.
my plan is to accommodate the balas with a 75 gallon tank in the future. the wall my tank is on is PERFECT right now. it's the spot i want the tank in (right in the middle of my living room), and it fits it like a glove. it's 50" wide and the tank is 48" wide. i know 72 or 75 gallon tanks are often the same width, just taller and deeper, so that is a possibility in the future, but going bigger than that is not likely unless we move or something.
here is a picture of the tank that gives you an idea of the size of all the fish. it looks different now though because i have slate in there instead of those rocks.
the bala swimming near the middle is the largest one. if i can't give them a larger tank myself then i will have to rehome them or turn them in. it's going to be a year or longer before they get too big anyway. right now i'd say two of them are about 4" and one is about 3".