I have the TFT100.
The basic OTO test (aka Taylor K-1000) says it tests for Total Chlorine.
Then there is the Chlorine Drop Test which will tell you Free Chlorine (FC).
Are these terms synonymous? Is FC the same as TC? If not what is the relationship between the two?
The CYA chart indicates what your FC should be based on CYA. So it seems the important test is the FC.
What is the purpose of taking the TC readings?