Big b wont bite! What lures do I use and how do I use them?

I live in Austin, Texas, and I recently found a stream/river near my house (Barton Springs) that has very clear water. Standing on the bank, I can see several very large b, along with some medium sized ones. I picked up some equipment, including 3/0 sized hooks, Zoom baby brush hog plastic lures (green), plastic worms (green), and black frog shaped plastic lures with neon green tails. All these pieces of equipment were recommended by an Academy employee. I have also used live worms. I have had absolutely no luck with these baits; I can see the b, and I drop the lure right in front of their faces (or near them), but they take no interest at all. I have only had luck catching a few small b using Powerbait Atomic Teaser lures. I am dying to catch one of these monsters, but nothing I use interests them at all. Please give me some tips on what to use and how to use it!!