I would believe your CYA numbers since you haven't added any. If you have added it is my understanding that it takes awhile for the CYA to dissolve and get mixed well.

I would say to keep ahead of the curve and keep the FC up until you get some CYA. The sun will burn through your chlorine super fast without CYA so you might add it several times a day.

Post some pictures, I would like to see your set-up. Sounds like a great pool.