I don’t have any suggestions for you reguarding your air consumption, in fact I have the exact same problem as you. However, I am a new diver and I am told that as I become more relaxed and comfortable with diving, my sac rate should improve dramatically. That having been said tho, you have alot of loged dives, and you are still having difficulities with your sac rate? If you do get any good suggestions on improvement, is there any chance you can pass them allong to me? Iappriciate your time, take care, dive often, and dive safe!