I am sure this has been hashed about countless times, but it is bugging me now.
After having just finished a new plaster interior Memorial Day weekend, we had 14,000 gallons of water trucked in and the rest from our water company via hoses. So now I have been trying to get the chemistry under control. I purchased a TF-100 probably in late August last year so the chemicals are about 10 months old.
In looking at hardness, my testing showed a 140ppm just a couple days after the fill. I tested again the following day and I had a 150ppm reading. On that day and for the next two days I added 10lbs of CaCl for a total of 30lbs. Now I show 250ppm which I am happy with, but the pool store shows me at 350-400ppm. They use what I think is called Pinpoint. They have small plastic, foil sealed, square vials with a measured amount of powdered chemical on the bottom. They manually aspirate some of my pool water into the vial, shake, and place on a back lit device with color squares.
Similarly, I show a TA of 80, but they say 120.
And I show a high pH at or near 8.2, but they say lower - at or below 7.8.
I asked why my readings were different and he blamed my last year's chemicals. I am not sure I buy into that excuse. Am I testing things wrong? I certainly have questions about colors. The red in the TA is more like a deep pink. And how blue is blue in CH? When I see no red 'flecks' in the water after mixing, I consider this blue - but it is more of a sky blue, not like food coloring blue. I need to break out my 64 count crayola crayons to get the names for the colors.
I think my signature will show the details of my pool, but here is the summary of my readings...
FC: 0.75 (on its way back up, had a huge upswing*, then over compensated)
pH: 8.2 (not trusting pool store, I added 32oz of muratic acid)
CYA: <30 (not concerned with this quite yet)
*another question, does the CaCl increase my FC?