hey guys, my cya has been running 35-40, we got 5 inches of rain in about 2 hrs a week ago, i go and check my cya today and it said 15-20, checked it twice, i do have an overflow drain, so the rain brought the pool up about 1 1/2 inches before it started going in the overflow that day, does this much rain usually make the cya fall that much ? ( testing done with the tf-100)