Welcome to TFF.
With that combination (Tiger Barbs and BGK) it will only be a matter of time before the BGK is dead. Tiger Barbs are nippy fish and should never be combined with any sedate or long fin fish, and the BGK is both of those.
As you are a new member, I have no idea of your level of knowledge or experience, so I will just point out that the BGK needs a tank that is six feet in length, and two feet width (front to back). This fish will reach 24 inches (60 cm) and being inflexible will not be able to turn around in anything less than a 6 by 2 foot tank. This fish also needs very dim lighting (floating plants can achieve this), and places where it can escape and hide just to maintain its own health free of stress.
Tankmates are not easy, but given the small tank here I would not get any other fish until you have the larger tank (assume you may not, yet) so the BGK is properly housed.