rainbofish behavior question

Rainbows are quite randy, that is normal. It would be better to have more females than males. A single female is likely to be chased to exhaustion. These fish breed daily.

Huh, that's weird. I read that a good breeding group for rainbowfish is 3 males and 2 females.

The reasoning they gave was that the males will compete with each other trying to impress the females. So they will not just chase after the female but will try and keep the other males from getting near her. And three of them so if one of the males is obviously the stronger one, then he can spread his aggression against two males instead of one.

But I don't know from experience. And RTR has a lot of dwarf neons, so go with him.

RTR, what do you think about the info I was given?

It's likely because you have only two - and of opposite sex. She will likely get tired of his amorous activities. Plus, rainbowfish are a schooling fish...ideally you should have more. If you have room, get at least one more.

Watcher, I don't' think there is a hard-fast rule about what works and what won't. I'm sure your suggestion would work as well. If I were less concerned about breeding (or wanted more of the "display" quality of the males) I'd do that combo. I've never personally had a problem with having more males than females...I have 5 male celebese and 2 females. If you really wanted to be sure about getting offspring, more females may work better only because you up the chances of something going correctly.

That said, rainbowfish are just very active and rambunctious. I'm watching my boesmanis as I type and they are at it again with their continual displays.

That ratio works well for both maximum production and "selction" of the fittest male in a breeder tank short-term. So it is full valid, but I don't do that process. In a permanent setting (I don't move rainbows to breed, I just move spawning mops or Java Moss covered "fence posts" from their permanent home to a hatch tank when I want to increase production) I like a surplus of females - even though they are less colorful. I routinely breed only in the circulating range, with "safe" tanks both up- and downstream. Chance fry survive there and supply enough to keep up the colony. As I do mostly species tanks, the "simpler" process (strictly in terms of my setups and the time I have to devote to them) works for me.