<a href=showthread.php?s=&postid=12883658#post12883658 target=_blank>Originally posted</a> by Peter Eichler
I don't suggest people keep firefish in groups in all but very large aquariums. In an aquarium a group of them will often result in having one dominant fish left as time goes on. As peaceful as they are towards other fish, they can and will become very aggressive towards conspecifics and are often relentless in their pursuit of one another.
Also, I don't find them to be prone to ich nor that short lived. 5+ years isn't unheard of for a lifespan in captivity.