Your tank is not big enough to house a BGK nor Clown loaches, and the BGK wont get along with the clowns either, especially in that small of a tank.
Clowns also require a school of 5 or more as they are a very social fish, but again your tank is too small to house even the 3 let alone 5
Clowns also require a school of 5 or more as they are a very social fish, but again your tank is too small to house even the 3 let alone 5