I'm growing a bamboo plant in a water storage tank and would prefer it to
bush out a lot more. At the moment it has one main tall shoot and a couple
of tiny ones.

Would it help it to bush out if I just trimmed six inches or so off this
tall shoot?

I know that this often works with plants, but around september of last year
I did trim the top off another bamboo in a big pot that was growing too tall
and after that the particular shoot in question just seemed to lose heart
and the leaves just stopped filling out.

So what I did in this case seemed not to be a good idea. So I'm wondering if
the trimming is likely to cause this to happen again or in this case the
bamboo was too near the end of the growing period?