Is there any way to calibrate the rachio flow sensor readings? I just installed a toro TFS-100 as per instructions with about 15" of straight pipe before the sensor and 7" after the sensor and when I compared the actual usage from my water meter to that of the flow meter and rachio app it is consistently short. 32 gallons via meter displayed as 25 gallons on the total water usage on the app. I've checked the utility meter with a 5 gallon bucket and it's dead accurate. What should I do?