Yeah, the K2005 has the color match chlorine test instead of the FAS-DPD method in the K2006. The FAS method is the only practical method for homeowners (or pool stores) to use to measure levels of chlorine above 5 ppm . . . and if you check the "Best Guess" chart, you'll need you need levels above 5 pretty quickly, as your CYA level rises.

However, if you are not having problems now, and avoid adding more stabilizer, you should be fine through the end of the season.