Whats the water clarity like? If you are fishing clear water then that is probably the first and biggest obstacle you may be facing. I fish a lot of deep clear gravel pits and your best bet will usually be a weightless senko in a natural color such as black, green pumpkin or watermelon seed or no seed. Cast it let it sink on slack line and kinda give it a jerk upwards every ten seconds or so and repeat. You may see results if not the its the old trial and error that we all face as anglers. Tight lines!