If it's reading the highest on the tester, it means it is 8.2 or higher. You can use dry acid to lower it, but it may take quite a bit.That's okay, you need it to be between 7.2 and 7.8.

Your FC level is based on your CYA, so you need a good number for your stabilizer level in order to determine where your FC should be. (See the "best guess chlorine chart" linked in my sig above for more explanation and the chart).

If you could run a set of test results, with a drop-based kit (no strips!) and post them here for us, it would be easier to help answer your questions. You definitely need to know your CYA level, though, and strips are useless for getting an accurate number.

Janet