As said before, they eat like crazy. I have six, 3 male, 3 female, and they are always picking at little things hroughout the tank. Eating stuff that gets stuck on my plants, java moss especially, and eating stuff on the substrate.
In my experience they will only school when frightened, like if I accidentally bump the tank or something, other than that they all do their own thing.
If water conditions are good, early morning when the lights come on, the males will display to the females by stretching out their fins and showing them the bright yellow stripe down the front of their head, trying to get them to spawn.
I have 6 of these in my 75 gallon. You should keep 2 females per male if mixing sexes. Males are deep-bodied when mature and have red fins. Females are more slender when mature and have yellow or orange fins. Although they aren't the tightest of schoolers, they definitely seem to feel better when kept in schools. I've noticed they are very powerful swimmers, they cover a lot of ground with just one slight caudal fin movement.
These are a great fish, I recommend them for a 4 ft tank as adults since they love movement and swimming into a current doesn't seem to satisfy their need for it. They are very hardy and very good for planted tanks as they will neither uproot plants nor will they harass your clean up crew. They bring allot of color and personality to any tank. In my experience though to really thrive they need large numbers, 9 or 12 to behave in a truly engaging and natural way. without the school they are more prone to acting like a gourami on speed. This tends to generate more stress in the tank as they will start to stick their nose where it doesn't belong, pestering your clean up crew etc.
Beautiful specimen in all regards. Hardy, good eater, excels with higher current. Flashes body color frequently in good lighting. Males also display frequently with healthy water conditions towards females. Body shimmers blue purple and green when fed a proper diet and good water quality. Male fins are bright red as well under good conditions. As said before, powerful swimmer. Schools well with a decent grouping. i have 8 in a 29 gallon and where one goes, the others follow. they often "hover" in a pack when resting
I am very tempted to get 5 or 6 of these in my 30g! Wondering if they meander more towards the top or middle? I have quite a few mid and bottom dwellers and am dying for a rainbow to go on the top thats good for a smaller, community tank.