Hello,
I started a thread a few weeks ago to get my halfbeaks identified, you'll find pictures, movies, and information at the links below. To cut a long story short, mine were not true Celebes halfbeaks,
Nomorhamphus liemi -- they had straight beaks and red fins with black spots but no blue patches.
halfbeak identification, please
Mystery halfbeaks identified
In the end it turned out I most probably have
Nomorhamphus ebrardtii.
Mine will swim to the bottom if there's some interesting food down there, and I've even seen them scoop stuff off the sand. But normally they're at the top, and if you halfbeak is always at the bottom it may be a sign something is wrong. They seem to like plants; I use floating
Ceratophyllum and the long leaves of
Vallisneria for this. A single halfbeak is probably not a good idea either. While they sometimes fight like heck (see the movies on my posts), they also seem sociable at other times. I'd have at least one male with 2 or 3 females, perhaps more if you have a big tank. Both sexes fight, by the way, so don't overcrowd.
Cheers,
Neale