Not sure if this is the correct place, but its on my acoustic so here it goes.

I get fret buzz only on my 5th (A) string on the 2nd, 3rd, and 4th frets only. The 3rd fret being the worst for the buzz.

Since its not electric i can't adjust the bridge so what can i do?

Guitar is fairly new, got it about 9 months ago. Thanks
I had the same problem on my new acoustic guitar.
It came with 11 gauge strings. I changed them to 13 and it the buzz was gone.

If you don't want to change to higher gauge strings you should get your guitar properly set up by a luthier. Fret buzz might be caused with loose fret, neck angle or low action.
Also, look at the nut. Is that string sitting lower in the nut compared to the others?

Another place to look is how the string is wound on the tuning peg -- is it spiraling down towards the head, or up (incorrect)?
rdsmith3 has some good thoughts. it could also be a high fret.

btw, many guitars are only made to take light strings, so be careful when changing to 13s. they could damage your guitar over time. also will change how the rest of the guitar plays, and may require not only lowering the action but also widening the slots in the nut.
Have you changed the strings recently?
Ultimate Guitar Set Up Q&A Thread─┤