I bought two Bala Sharks about a year ago, one large and one medium. They have been a joy to have! They are excellent for large community setups, providing there aren't very small fish around (I've lost more than one Neon to them). Mine have not been aggressive or territorial. They just like to swim around together. After having a massacre from a "killer" catfish, they and a few other fish are left. Bala's are incredibly resilient. About three months ago, the larger of the two Balas (he is about 13 cm long) got himself stuck in a small hole in one of the lava rocks in my tank. He thrashed about until someone came to rescue him. He was very badly torn and we thought he would lose one of his eyes, but amazingly enough, he survived and has mended very nicely. I love my sharks and would not give them up for anything!
Active yet peaceful, Balas make a wonderful addition to any large sized community tank; unlike many large fish considered "peaceful", these guys won't eat or harass small fish such as Neons. After they become familiar with you, many will eat right out of your hand, although sharp movements will still startle them badly. Don't be surprised if you hear a very loud clicking or snapping sound. It's just the Balas munching up bits of food. When I first heard this noise I thought my tank was cracking!
To an earlier comment about the Balas showing early signs of Ich by scratching their scales against objects, that is what is known as flukes and needs to be treated accordingly, ideally in another (medicine) tank. Another telltale sign for this common disease is excessive breathing and short quick bursts of speed. Ich usually makes its presence known with small white spots.
This is one of my favorite fish. VERY PEACEFUL! With their sleek and shiny silver bodies, they can really add a lot of personality to the tank. Speaking of personality, these fish are entertaining. I originally had 1 Bala in a 100 L. He would swim around, constantly searching for food and just full of energy, to the point of possibly acting hyper. However, due to the suggestions I read posted on this website, I decided to add a couple more. Now they do the slow swimming schooling behavior that I was looking for. Right now mine range from 8 cm to 12 cm. I've already began planning on getting a bigger tank to house these guys when they reach full maturity. They get along great with all their tank mates. And you gotta love that lip-smacking, clicking sound they make on the surface.
I have two Bala Sharks and they are the best thing in the tank. One of them is about 15 cm long and the other one is just a baby (5 cm). Their favorite food is Spirulina discs as anyone that has heard a Bala smack his food off the top will love this, he picks up the disc and smacks it off the rocks. The two work as a team, sometimes the disc gets stuck in small spots and requires the little guy to get it out, and sometimes the Colombian Sharks want it and won't let the little one eat so my big Bala swims up in there and smacks the disc so loud that the big Sharks run for it. The little one is also somewhat of a helper to the Iridescent Shark I have, the Iridescent is starting to lose his sight and can't find his flakes as well. The little Bala allows him to sit on his back and kind of guides him to the food. The Iridescent´s stomach gets so full he can barely swim afterwards. Word to the wise: Do not introduce baby tiger barbs when your bala has a huge tail. My baby Tiger Barb bit the big Bala´s tail and ended up missing half of his body. I guess the baby saw his tail and thought it was a good idea to nip at it. Bala's eyes went pitch black, as they tend to when he's mad. The little Tiger Barb went to swim up to the top and Bala, being a strong aggressive swimmer, in two swishes of his tail was at the top and had taken a bite right out of the poor little nipping devil, and ended his life right there. Needless to say all the Tiger Barbs don't tend to mess with him anymore. Bala's are innocent, right, you would have freaked when you heard the crunch of the bones. CRUNCH!
I tend to have some disagreement with some comments mentioned above about the Bala. My experience has been that Balas are indeed peaceful and docile, but they are *not* easy to keep for beginners. Balas tend to spook easily, are a "nervous" fish unless kept in large schools, will hug the bottom of a strongly lit tank, will cower from fish that have learned the Bala won't defend itself, and can't tolerate fluctuations in ammonia which will kill them in short order. Unlike other species, the Bala is certainly a better fish when it gets over 12 cm in size. At this point, they seem to become hardier and more bold while retaining their impressive looks. I've seen this species over 20 cm in length in large tanks, and they are gorgeous.