I've just drained and refilled my hot tub for the first time. Our tap water has calcium hardness of only about 10ppm. I measured it with the taylor kit, and as it should, the solution turned from red to blue on the second drop.
So, I added some 'calcium hardness plus', intending to bring the level up to ~100ppm. According to the package, I needed a little over 20g for an 90ppm increase. So, I added that, waited for it to circulate and then tried to test again.
This time though, when I added the reagent that's supposed to turn the sample red, instead of turning a dark red as it did when I had originally tested the water, it only turned a very light red. Then when I added the titrating agent, after about 4 drops the sample turned clear instead of blue.
I'm not sure how to interpret this. The only case I know of where the sample would not turn red is if there is insignificant CH in the water. But it worked fine with the original water, and if anything the level should now be higher.
Does anyone know what's going on here? The Taylor instructions describe what to do if the sample turns purple instead of blue, but not if it doesn't turn red in the first place. I also tried eyeballing it with test strips, and as far as I can tell from those, if they're accurate, the CH level is now between 40 and 80 or so. I've never known strips to be more accurate than the titration though.
So, I added some 'calcium hardness plus', intending to bring the level up to ~100ppm. According to the package, I needed a little over 20g for an 90ppm increase. So, I added that, waited for it to circulate and then tried to test again.
This time though, when I added the reagent that's supposed to turn the sample red, instead of turning a dark red as it did when I had originally tested the water, it only turned a very light red. Then when I added the titrating agent, after about 4 drops the sample turned clear instead of blue.
I'm not sure how to interpret this. The only case I know of where the sample would not turn red is if there is insignificant CH in the water. But it worked fine with the original water, and if anything the level should now be higher.
Does anyone know what's going on here? The Taylor instructions describe what to do if the sample turns purple instead of blue, but not if it doesn't turn red in the first place. I also tried eyeballing it with test strips, and as far as I can tell from those, if they're accurate, the CH level is now between 40 and 80 or so. I've never known strips to be more accurate than the titration though.
