Fret buzz only on the 2nd fret of the G string?
 

I have my bass set up for pretty low action now. I am convinced the relief is set correctly. All the other frets on the bass can be played without buzz except for the 2nd fret on the g string.

From what I know, this usually means the 2nd fret is too low or the 3rd fret is too high. I am not a pro, but from what I can see both the frets seem fine.

help!

Yes, that is what it should mean.

Best thing to examine this problem is a StewMac "fret rocker". It's a little triangular metal thingie with differnet length straight edges on the various sides. What you do is bridge it across three frets and if the one in the center is high it rocks back and forth like a teeter-totter.

Once you find the high fret you either need a fret file to file it down or a a total fret leveling, crowning and setup by a luthier. If it's just a single fret with a problem a little filing usually does it.