Knowing that having a CH of 0 is nearly an impossibility, I decided to do some more testing and experimentation.
I am using two test kits. Primarily the TF-100 and an hth 6 way from Walmart as a sort of confirmation.
Using either test kit, if I fill the vial to 25ml with pool water and add the five drops of indicator, the solution does NOT turn red, or pink. It is a very light blue from the get go. Supposed indicating 0 hardness.
So I decided to dilute the sample with distilled water. Interesting thing is that the diluted solution DOES turn pink. (Yes I verified that the distilled water alone has 0 hardness, which is expected.)
The first go around I used 5ml of pool water and filled up to the 25ml line with distilled water. So a dilution of 1:5. Using either test kit, instead of multiplying the drops by 10, I multiplied by 50. 3 drops = 150 CH.
The second go around I used 12.5ml of pool water and fill up to the 25ml line with distilled water. So a dilution of 1:2. Using either test kit, instead of multiplying the drops by 10, I multiplied by 20. 6 drops = 120 CH.
So, I am thinking, there must be some chemical in the water that is throwing off the CH test when I don't dilute the sample. By diluting the sample, I am now able to get some results.