Need advice on some recent weirdness with my CH test. I've been using the TF-100 for the past three years. First kit was purchased in Spring 2017, refill purchased in Spring 2018. I did not buy a new kit last year because I had plenty and the reagents last two years. Bought a new kit this year (full kit).
Over the past 3 years, my CH has consistently tested between 250 and 350 each week. From splashing, backwashing, winterizing, etc., it might drop to 275, and I'd add some calcium chloride to get it up to 325-ish. I haven't added that much -- maybe 8 lbs or so per year over the past three years (4 in the spring, 4 in mid-summer). Last test with the old reagent showed a CH of 300, which is about where I like to be.
I got my new TF-100 test kit in the mail last week. First test with the new reagents showed CH of 650! Thinking I had screwed something up, I did another test and got 600. Worse, my TA was showing 120 (PH and TA always run high in my pool from waterfall, fountain, waterslide, and kids -- I typically add 1 gal of acid per week during the summer). It started raining so I gave up. Yesterday, I ran the tests again, slowly and methodically, side by side with the old reagents. Test with the old reagent showed CH of 300. Test with new reagent showed CH of 525. Notably, the change from red to blue with the new reagent was not instantaneous, as it was with the old -- I would drip, swirl, and then the solution would change color 10-15 seconds later. I ran both tests again, this time swirling then waiting 10-15 seconds before the next drop. Got 300 again with the old reagents (instant change), 525 with the new (~15 seconds after 21st drip and swirl).
Anyone have an idea what's going on, and what my real CH levels are? My first thought was that the ~2 yr old reagents had gone bad, and that the new reagents are giving me the accurate results. But the delay in the color change combined with the more consistent results from my old reagents have me second guessing myself. No new visible scaling and my CSI is currently OK, but I have been adding acid more frequently to keep the PH down and the CSI within recommended range. Appreciate your thoughts.
Over the past 3 years, my CH has consistently tested between 250 and 350 each week. From splashing, backwashing, winterizing, etc., it might drop to 275, and I'd add some calcium chloride to get it up to 325-ish. I haven't added that much -- maybe 8 lbs or so per year over the past three years (4 in the spring, 4 in mid-summer). Last test with the old reagent showed a CH of 300, which is about where I like to be.
I got my new TF-100 test kit in the mail last week. First test with the new reagents showed CH of 650! Thinking I had screwed something up, I did another test and got 600. Worse, my TA was showing 120 (PH and TA always run high in my pool from waterfall, fountain, waterslide, and kids -- I typically add 1 gal of acid per week during the summer). It started raining so I gave up. Yesterday, I ran the tests again, slowly and methodically, side by side with the old reagents. Test with the old reagent showed CH of 300. Test with new reagent showed CH of 525. Notably, the change from red to blue with the new reagent was not instantaneous, as it was with the old -- I would drip, swirl, and then the solution would change color 10-15 seconds later. I ran both tests again, this time swirling then waiting 10-15 seconds before the next drop. Got 300 again with the old reagents (instant change), 525 with the new (~15 seconds after 21st drip and swirl).
Anyone have an idea what's going on, and what my real CH levels are? My first thought was that the ~2 yr old reagents had gone bad, and that the new reagents are giving me the accurate results. But the delay in the color change combined with the more consistent results from my old reagents have me second guessing myself. No new visible scaling and my CSI is currently OK, but I have been adding acid more frequently to keep the PH down and the CSI within recommended range. Appreciate your thoughts.