If you had no overnight chlorine loss and the pump was running, there's no need to test again with the pump off. Your loss appears to be just during the day and usually that would indicate that your CYA is too low. However, you are measuring 60-70 ppm for the CYA. So I'm at a loss to explain this assuming measurements are correct. Since your overnight loss did decline now to near zero, how's your daytime loss now? Probably still high, but is it as high as before? At 60-70 ppm CYA, even in Arizona sun you should be losing less than half the FC amount per day so with a minimum of 5 ppm FC you would start at 10 ppm FC and lose 5 ppm, but in practice it should be more like going from 8 or 9 ppm FC to 5 ppm for a 3-4 ppm FC loss at most. To get lower than that in full Arizona sun, an 80 ppm CYA might be needed, but it just seems like your loss is higher than normal for some unexplained reason.