OK, kids, here's my latest question.

I have a 55g community tank. Currently weirdly (but pleasingly and healthily) stocked as a community tank which I have been thinking of evolving toward an Asia region tank. The key word there being "evolving," mostly because I like my current fish and, barring something drastic, will probably let most of them live out their lives before replacing them.

I have a small school of five turquoise rainbows, two males and three females. They are about two-three years old, lovely colored and appear to be healthy--they even spawn occasionally. The only indication of any problem is that they have not reached their full size. I have been told that a 55 is too small for TRs; the excepted wisdom seems to be that a 55 is acceptable but probably the minimum. I hope that is the case because there is no chance of re-housing them in larger quarters at this point.

Lately, I am considering going a different direction, evolving my tank toward an all (or mostly) rainbow tank. I'm talking the Melanotaenia types--I don't much care for the looks of blue eyes, thread fins, et al.

So, what's the lowdown on Melanotaenia in 55g? Assuming I found new homes for all my current critters except a couple of my bottom feeders, would it be realistic to add some other types? The obvious choice is a school of praecox. But I really, really like boesemans (though I have no idea how to say it), red Irians, and some of the more colorful Australian types.

Seems to me the trouble would be that they do best in schools, both aesthetically and for their own health. Adding six or more of a couple different varieties would leave my tank seriously overstocked. Adding only one variety (or simply building a big school of Turquoise) would make more sense health wise, but wouldn't look as pretty--I like having fish of contrasting colors. But I think a smallish school or boesmans or Irians would do the trick aesthetically.

Thoughts? Suggestions? Just kicking it around right now. I especially prefer to hear from people with personal experience. Thanks!