CH test reads 0?

[waterbear]

Hmmm.....just repeated the test myself and then checked it against my Taylor kit and a test strip. Here is how it went:
Aquachem kit
added 2 drops and water turned yellow( as it has in the past with 2 drops). Continued adding drops until it turned violet red...took 14 drops.
titrated and got 350 ppm (7th drop turned blue, 8th drop no change).
repeated test with 20 drops of indicator and got between 300-350 ppm (6 drops changed to blue but 7th drop made it a bit deeper, 8th drop no change)

Taylor kit...got 200 ppm which is what I believe it should be based on what it was last test and the amount of calcium chloride I just added to the pool recently. (Yes, I know you don't need calcium in a fiberglass pool but my fill water has 0 ppm calcium hardness and I have a heater)

tested with a strip which tests for TOTAL hardness (calcium and magnesium hardness) and got a bit higher than 250 pppm total hardness (strip color chart goes from 250 ppm to 1000 ppm...not much accuracy here)

Now I wonder if the Aquachem kit might be testing for total hardness and not calcium hardness. The Taylor test for total hardness is a 2 reagent test. (indicator and titrant)

Also, the last time I tried this (my CH level was at 140 with the Taylor) it only took 8-10 drops of the indicator to get a violet red color and the results were much closer to the Taylor test...I assumed it was the difference in accuracy of 10 ppm for the Taylor and 50 ppn for the Aquachem.

Anyone have any thoughts on this?