I've got six tiger barbs in a tank 4 feet long 18 inches tall and 1 foot wide. I have a bunch of other misc. fish like danios but am going to put them in another tank. Which would be better to add to the tiger tank, clown loachs or a red-tailed black shark. My tigers are quite aggressive and have already driven many tetras to suicide via aquaclear filter. Clowns and the shark are both omniferious but don't take into account algea eating ability as even with a full spectrum light I've been uncapable of building algae.