I'd love to but he's pretty aggressive. They have different water preferences too, the goldfish is in colder, filtered water with lots of water agitation. I couldn't take away the filter as the ammonia and nitrate levels would build up and I won't use chlor-out in the goldfish tank because when I did use it the goldfish got real sickly. I don't think that a male betta can live with females, it'd be too stressful on the fish.