I have 2 balas. One is about 10 cm and the other 7 cm. Before I introduced them to my tank, I had snails. I never saw the Balas eat them, but I haven't seen one since the third day after I had them. As far as feeding them zucchini (like all the websites say), mine don't touch it. Seems they like blood worms, like every other fish my tank. About 5-10 minutes after the initial feeding frenzy, they go up to the top of the tank to get the worms 'sticking' to the sides. That's when the 'clicking' noises are at their best. The smaller one makes much louder noises, too. Awesome fish to watch, as well.
I have had my 2 balas for several months now and have thoroughly enjoyed keeping them. They have gotten used to me feeding and pop to the surface whenever I come into my room to feed them and take food from my fingers. However, I find when it's time to clean the filter media I have to use plastic sheets to cover as much of the surface as I can. They will take every opportunity to jump for it, as I found out to my horror one day when the big one (approx. 14 cm) jumped at least a meter and was bouncing all over my room. He survived, to my surprise.
I have 3 Balas, ranging in size from about 18 cm down to 12 cm. Very friendly, very active. They swim around all day, looking for food. When I get up in the morning, they know it's feeding time, and gather front and center at the top of the tank. They do spook pretty easily, but the ordinary motions involved in feeding them doesn't seem to frighten them at all. They are the only top-dwelling fish in my tank.
I have 4 Bala Sharks about 12cm. I have recently upgraded them from a 115 L tank to 380 L. The water stability and additional space has made an incredible difference to the little fellas. They are no longer nervous and the strange yellowness in their fins and tails has disappeared. They school and play together happily and have made a submerged tree branch their new home. They have a good chase around for 15 mins after each feed and then gravel search together, leaving no stone unturned. They have proved very hardy with an adorable temperament.
I have had my Bala for about 4 years now. I have him in a 720 liter tank so plenty of room for him. He is a peaceful, shy fish, but gets on well with the clown loaches. They almost seem to tease each other, on saying shy it is to my great delight that he is starting to take food from my hand like my other fish. And it's true, they do circle around beneath the food like real sharks. A joy to have in any large tank.
I have 3 Bala Sharks in a heavily planted 900 L comunity tank. Some of their tank buddies include a huge (50 cm) Arowana, a Black Shark, a large Pleco, a Siamese Tigerfish and many more. Bala sharks in my experience have been very peaceful, laidback fish. I feed them on flake food and occasionally live food. I bought them at a very young age (about the size of a small guppy). Originally I had 4, but one was eaten by my Gold Arowana. I have had them for over 3 years now and I have never once had a problem with them. If you are looking to buy a large tropical setup or just get some new fish, Balas are the fish for you.