PVC is what I'll be using. My only problem is that I won't be able to run it under the walkway due to not being accessible because of the water level. I'm planning on running it down the left side, but I don't have anything right now to support it too except the post and I'll need some support in between the post. I'll either have to get some sort of bracket or have them nail another piece of 2x12 treated on the outside of the post for me to run my conduit on. Got to have something that won't make it look too tacky.