um, "Nobody"... I'm just a novice, but isn't your 40 gal hex way too stocked? Maybe if you took the bala sharks out it wouldn't, but with them in, that's already around 30". As far as I've found, a good rule of thumb is 1 inch of fish per gallon.
We have a 46 bowfront and really wanted a few bala's but we decided against it, because a couple years later we'd have to give them away, unless they were the only ones in the tank. As straitjacket said, they really need 100gal tank.
Just my 2 cents, if it means anything