Birospira jump starts the cycle, but you still need to keep testing to make sure it took. You will know it worked when you see 0 ammonia, 0 nitrite, and some nitrates. Sometimes birospira doesn't work, as it is alive it can die due to mishandling.
As for tiger barbs, it is nice to have some plants or decorations for them to hide in, as smaller/weaker barbs will be chased. They also like open space to chase each other around.
Oh and they always act like they are hungry--don't be fooled they don't need more food. When I come to look at them they all come to the top for food, even if I've just fed them.