I think I will just keep it for a quarantine tank. I mean, if I felt my one betta wasn't doing well in it, why would I put a new one in the same position? Also, I figured I would share and update; came home after being gone for several hours, nervous that the filter might have caught the betta, (he was quite interested in it earlier. Kept staring at it). However, rather than being hurt, he had built a few small bubble nests in different spots. Nothing too big, but it is something he didn't do at all in the last tank, and has been in the new one for less than a day. So I guess he is happy.