As Chris says try slapping the rig on the surface to fool the fish into thinking it's naturally hitting the water, bites using this method can be instant,
As for rigs I Mysell fish a bit lighter though, Preston PB2 Carp 4x10 or if it's a bit choppy 4x12 on 0.13 straight through and a Preston PR36 size 18 hook with a hair rigged Mossella Micro band,
For a typical match I'll have 3 4x10 and 3 4x12 shallow rigs set up,
2 at 12" deep, 2 at 18" deep and 2 at 2'6" deep, I use grey Hydro for most of the work,