Who knows what's in the Enhanced Shock? SpaGuard and the MSDS don't say. And you may have to use less of the Chlorinating Concentrate which would cost less per use.
As you indicated earlier, and the Taylor website says, "to achieve accurate readings for combined chlorine the MPS interference had to be eliminated." Since I already have the other reagents in the Taylor kit you mentioned, I am going to order some of the deox, R-0687, and then run a combined chlorine test. If I am still getting high CC after that, I may give the Chlorinating Concentrate a shot.
And for the record, I am glad I got a Taylor kit as suggested on the forum. I use strips only for quick checks.
Thanks. I am still learning, and your input has been very helpful.