Well, I just introduced my blue crowntail betta into my ten gallon with my cory cat (I know, I am getting a couple more when the LFS gets them in next week
). So far he has been exploring the tank, flaring at his refelection. He has only noticed the cory cat once, flared at him and chased him for a second and then seemed disinterested. I bought the cory a cave also to hide in. The betta I "rescued" from our local Petco last week. He seems very healthy though. So, if all goes well the betta will be fine with the cory cat?

