The water is low and clear and the fish are spooky. Try a longer leader with a small black or some other dull color corkie with a small piece of prawn for scent only. better if you make the prawn a little strip that wiggles. The most important thing though is to NOT bang the bottom. Use a very small weight which will move fast through the drift and not let them have a good look at it. They seem to be more apt to hit something they only have a split second to react on. Keep the drag loose too because they can be out of the water and running as fast as you feel them.