I concur. You could double that number with no problems in a 29g. This is a very quiet, sedate fish, and they live in groups of thousands.
Observations in their habitat have shown that in a well-planted environment, or one thick with branches (which is more common), they remain in groups of 5-6 within the larger shoal. Once they get into more open areas, they congregate closely together in the thousands. The point of all this is that you can never have too many, at least not for the fish themselves.