TF 100 TC, CC and FC question

[Thinkly]

I am a bit confused. With the TF100 kit you get the combined unit that measures TC and pH together at the same time. Then you can also do the drop test to obtain FC and subsequently CC. My understanding is that TC - CC= FC.

So why do I need to know my TC from the initial TC/pH test? Why does TC really even matter, if the drop test gives me FC and CC results? After all TC really doesn't matter with respect to the other two does it? I could see if you didn't have the drop test for CC you would need it but don't understand the point in the TC test with the TF100.

 

[baudilus]

Assuming you have no CC, then TC and FC are interchangeable, in which case you can use the TC test as a FC test.

 

[257WbyMag]

I believe that the test block for ph and chlorine that is included with the TF-100 is for the OTO chlorine test. The OTO test is a surefire way to confirm whether of not you have chlorine but it won't allow differentiation between CC and FC. Only a DPD chlorine test can allow that. To find your FC and CC, you would want to the the FAS-DPD (drop test using the test tube and not the test block).

 

[Bama Rambler]

Not speaking for Dave but I'm sure it was done to give you a relaible pH test and since you can't get a drop pH test vial alone, the next best thing is the K-1000 combo. As mentioned before the OTO test is a good go/no-go test for chlorine no matter how high it is.

 

[JasonLion]

The idea is that you use the OTO chlorine test every day and only use the FAS-DPD chlorine test once a week or when you suspect problems. On the other hand, many people here prefer to use the FAS-DPD test every time.

Using the OTO test daily doesn't really start working until you get used to your pool and know what to expect and how much chlorine you usually need to add. At that point, you can skip the FAS-DPD chlorine test and just use the OTO chlorine test for a quick check that nothing is dramatically wrong. If the OTO test is way to low, you know something is up and use the FAS-DPD test, but if the OTO test is a nice yellow you just assume that everything is fine and add the routine amount of chlorine.