Hi,
I have a 15 X42 AG 3900 gal
I only have the WalMart HTH 6 way kit but just ordered the TF100. Took a sample last Thursday to store results were:
FC .87
TC .86
PH 8.2 my reading at this time was off the chart
Calcium Hardness 310
TA 280 mine around 320
CYA 30 mine the black dot did...