Could someone tell me what the best setting is on this unit for being able to actually see fish on the bottom or suspended. I can idle over ledges and see schools of bait but for some reason I never can see bass using it. The reason I'm mainly a little confused is because I have an old Lowrance lcx-26c in the dash and I can clearly see what I'm pretty sure are bass on it and have the 999 running at the same time on down and side imaging and it will not show anything at all.