Three weeks ago I changed my diet to reduce my sodium intake.  In retrospect, I probably reduced from over 30 grams to around 10 grams. How long will it take for me to see positive blood pressure results blood?

You may not see any decrease in your blood pressure by limiting your salt intake.  Not everyone with high blood pressure is sensitive to salt.  Salt sensitivity is difficult to measure and most of us eat too much salt.  Because of this, eating less salt is routinely recommended.