Well, to be perfectly honest, that doesn't sound like ich to me. Have you read this article?
http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=32
It is excellent. Look at the pictures. These pictures show what an infestation of ich will look like. Unfortunately, just like humans, there are many many diseases, parasites, bacterial and fungal infections, internal problems, etc that can affect fish.
Did his fins have black or white edges? This may have been a sign of fin rot. I am not an expert in this area, however. The only disease I have ever seen is ich and a white bacterial growth on some tetras. I wish I could help you more, really I do!
For right now, though, your best bet would be to describe exactly how the problem with the bala shark started, what your water parameters (ammonia, nitrite, nitrate, pH, etc) are, and exactly how the problem escalated to the point where the bala shark died. Colors, the way the fish looked, how his fins looked, etc. That way, another member with experience treating different ailments will be able to help you out!
But again, from what you have said, it doesn't really sound like ich.
Paul