I agree with Mduros on this one. Your best bet would be to get rid of the other fish and make the tank a brackishpuffer tank. They can handle the hex setup better than the others I think. Please don't wait until the bala and the pleco's are too big to rehome them. This will cause them to become stunted and will shorten their lifespan substantially. Rehome them while they are still small and this will prevent them from having future problems.