The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
They probably won't eat each other, but space will be a problem. Both the bichirs and barb probably need a bigger tank (especially if you have two bichirs).
Agreed with above. Tinfoil Barbs are schoolers and can get up to 14" long, making the space constraints even worse. Bichir tend to be territorial once full grown, so your two may get scrappy with each other if not given a sufficiently large tank to establish their own territories.