Originally posted by PumaWard
IME, they are very hardy. The one thing you have to be really careful about is that the water isn't too warm or they will slowly dwindle away, and may appear to have died without any reason.
I bought six last august, all are still well and they had even spawned in my tanks a few times.
Good tank mates for neons are bettas, blue rams, cory cats, guppies, mollies, swordtails, platies, cardinal tetras, red phantom tetras, smaller species of plecos like bulldogs and bushy noses, ottos... the list really goes on and on.