At least you are within ranges for your CSI. I definitely recommend the Speed Stir. Maybe that is why you are testing high. Only thing I can think of. The only other item is that if calcium was too low in the beginning, that calcium from the pool surface can dissolve into the water, causing pitting and deterioration.
Pool School - Calcium Scaling
You also stated that your test kit came in this year, but the pool has been around for a whole year prior to this.
Were you testing with something else from when pool was built to when you received the test kit? From August of 2014 to June of 2015, is it possible that your calcium levels were lower than you thought and calcium from the pool surface was dissolving into the water? If you were using test strips, they could read falsely high. Then maybe without the speed stir, you are getting a high reading.
You have a pool that requires accurate testing for CH and PH and the speed stir sure seems to be the next step.