Not hard to end up with various reports.
I haven't kept Columbian Tetras. They are quite attractive fish.
You need some ammonia asap, or there won't be any food for the bb to really get growing with. They need food, ammonia. Flake food can work for you but pure ammonia is cleaner, as there are particles from the flake food that are added to the tank.
As you probably noticed with people's responses to quick start bacteria additives, there are more varied reports. Most say little noticable help long term and just some short term bacteria strains which don't grow well or last long term. I am not a scientist and haven't ever measured any types. But did use some one time and can't say it was bad, but also didn't cycle the tank. (maybe it helped).
Really it boils down to the BB need to be present to be able to handle waste and keep the cycle going, more ammonia grows more BB if there are available surfaces for them to grow on. If there is room in your Penguin to add a second filter pad I would do it, creating double the surface area for the most possible BB to colonize. Always been a huge help in my tanks.
Good luck on your search for the correct stock combination. Time and experiences tell us there are numerous excellent fish stock combinations, and then there are other combinations possible. Also very bad ones. At least you can be sure SOMEONE will probably tell you if there is a really bad one!
Much has to do with numerous trips to the lfs to see the fish in a tank (probably terribly stressed and in poor color) and deciding your favorite and building (stocking) the tank around that first selection! Smart way to go.
Also as a side note, you will likely evolve in favorite fish choices over time.