Got to be one of the most miskept fish.
Always put in tiny tanks, most people don't know just how big they get! Properly kept, in at least a 100 gallon tank, they are great fish! Very peaceful, although balas, like any other fish, will eat any and all fish that are immensly smaller than themselves.
these giant minnows are great fish. they grow quickly, are very active, and are very peaceful. they do need a large tank. i refused to buy them until i had my 450 gallon tank set up. they would swim in pairs and sorta dance against each other down the length of the tank (10 feet) rather quickly, so i feel they would need an even bigger tank to be happy once reaching full size. i do believe that they are extinct in the wild and mainly exist in farms where they are bred for food and the aquarium hobby.
They are peaceful fish, though skittish as heck. I've got three that range between 3" and 6" - it took quite a while to earn their trust, and now that I transfered them to their own 90 gallon tank, they're back to scattering when I approach the tank. How annoying.
As far as a planted tank, just be aware that nothing pleases a Bala Shark more than rooting around the base of any plant you add to your aquarium, and uprooting plants (especialy tall plants) seems to be a Bala team sport.
These guys love schooling and grow huge! For these reasons, it is recommended that you have at least a 6 foot long tank. They are excellent community fish but as with all large fish, they should be watched around smaller tank mates.
2/27/2013 I have 2 that are about 1/2 grown in in my 125 gal. (6' long tank). When fully grown, I am not sure anything less than 400 gal would give enough room. Yes they are a bit skittish. My wife bought two of these ("because she liked them") while I was out of state for about a year. She did no research first. They just get too big for a 125 gal.