I think you misunderstand... I currently have a five gallon for my betta... I'm getting a new 50 gal for Xmas. ^^' Perhaps I wasn't clear enough. I do not plan to put my betta in the 50 gal at all. Also, Hangetsu, my Berta, is currently the sole inhabitant of said tank.

That said, I think I agree with you on the gouramis. I think I won't bother with them at all then. Also, RTBS stands for Red Tail Black Shark, which grows to 6" length. He can handle the barbs fairly well, I would think.

Do you know of any other fish to inhabit the top portion of the tank with/instead of the barbs? Any Semi-aggressive tankmate that can coexist with the Black Ghost Knife would be great.