They should be kept in typical tropical temps, around 80 degrees F, give or take a few. The tankmates sound okay, but the bettas might be seen as food.K626;1499327; said:Is there a proper temp for one to be kept in? I'll buy another heater if I have to. I have a rather open 55 gal, 3 1-2 inch angels, 2 female betta, 1 5-6 inch syno. I have a male betta in a box (a breeder box) in there too. Would this be suitable? If not, I have a 30 gal grow out with 2 ck's (4 inch) and a bgk (3 inch). I'd rather not put it in there though. Don't want too much competition for food. I feel my other tanks would be too small for it (20 gal tall, and eclipse 6).