I just did a CYA test. The black dot disappeared at about the halfway mark between 30-40 so I'd say it's 35.

The pool is I think around 12,000 gallons but I am horrible at remembering numbers. It's a shallow gunite pool with a pretty big tanning ledge. I don't have any kind of chemical equipment or anything. My filter is a cartridge filter and I have an ozonator. I've read that ozone depletes free chlorine and every FC reading I've ever done was pretty low.