Consider yourself to have luckily gotten enough residual chlorine to a) not have it breakdown, because all that CYA is slowing it down, and b) to have a residual to keep your pool clean!

Now you need to get your OWN test kit that can measure higher chlorine levels....You want something with FAS-DPD chlorine testing. That's Ben's kit, the PS-234, or Taylor's 2006 or Leslie's Chlorine FAS-DPD Service Test Kit. You can only get any of these on-line. You can instead just get the FAS-DPD test portion without the full kit. Both Taylor and Leslie's sell them on-line--I don't know if Ben does. All of Leslie's test kits are just rebadged Taylor kits anyway.

Or get a kit that goes to 5ppm of FC and hunt up the CarlD Shotglass Method in the forum!