As to my "guesstimate" of an FC of 20, it was based on the internet pool calculator that I have used numerous times with good results. Based on what I added 484 fl. oz. of 8.25% bleach and a starting FC of 8.2 the new level should have been 21 ppm. I did this at about 11:30 am, it is now 3:28 pm and I rechecked the FC as you recommended .... it came out to be 22.5 ppm. Instead of the bleach, how about a another bottle of chlorine titrating reagent (R-0871).

Be that as it may, it has been sunny but relatively cool down here in south Georgia, maybe that has something to do with it. I will continue to check and thanks for your confirmation of my approach and the tip that I can leave my SWCG system on.