It seems really out of whack to me, I've never seen a CC of 15. The test you have is a plastic square with two tubular rectangles at each end, with a color chart on it, correct?
Here's a step-by-step on how to use that kit if so:
Add water to the chlorine side of the block, make water or bottom of water meniscus is even with line near the top of the block.
Add 5 drops R-0001 and agitate
Add 5 drops R-0002 and agitate
Match color of solution to the scale. This is your free chlorine (FC)
Add 5 drops R-0003 and agitate
Match color to scale, this is your total chlorine (TC)
Subtract FC from TC to get CC (TC-FC=CC)
Here's a step-by-step on how to use that kit if so:
Add water to the chlorine side of the block, make water or bottom of water meniscus is even with line near the top of the block.
Add 5 drops R-0001 and agitate
Add 5 drops R-0002 and agitate
Match color of solution to the scale. This is your free chlorine (FC)
Add 5 drops R-0003 and agitate
Match color to scale, this is your total chlorine (TC)
Subtract FC from TC to get CC (TC-FC=CC)