I live in Phoenix, so we've always had high calcium hardness readings. I use Taylor testing reagents. After our yearly spring pool drain, I always bring a sample to Leslie's for comparison. Until a few years ago, Leslie's numbers weren't too far off from mine. But the past three summers, Leslie's readings for calcium hardness have been coming back at 250 when my Taylor reagent readings are 425. I tested my reagents against the hardness standard, and they were right on. This year I also went to a place that uses a digital probe, and they read the calcium hardness at 340. Just to be safe, this year I used fresh reagents, and got the same readings as the old reagent--425. (I keep my reagents in the house in a dark, cool location. )
At about the same time that Leslie changed testing methods, the numbers on the Total Dissolved Solids were higher than usual after a drain. I don't test for that at home, so I rely on Leslie's. This year the TDS reading at Leslie's and the digital probe reading were in line at about 1800-1900. About 1300 of that is salt according to Leslie's.
At the same time that I began getting wildly different readings from Leslie's, they began using a color wheel, which is read by a computer. When I asked Leslie's employees about the difference, they said Phoenix water is less hard now, something about the water source. It sounded like gibberish to me., so I checked with our local City water people, and they gave me the nearest location reading for total hardness that they have for the tap water. But their numbers include magnesium hardness, so they were getting about 200 on the total hardness in my area. I got a CH reading of 175 on the tap water that year with the Taylor reagents. The water quality guy at the City thought my numbers were probably more in line with what was actually going on. I'd agree except for this latest test with the digital probe that's read by a computer. Are reagents still the go-to for chemists as the most reliable method?
Thoughts? Should I use my numbers or go with the digital probe when calculating LSI?
Thanks.
At about the same time that Leslie changed testing methods, the numbers on the Total Dissolved Solids were higher than usual after a drain. I don't test for that at home, so I rely on Leslie's. This year the TDS reading at Leslie's and the digital probe reading were in line at about 1800-1900. About 1300 of that is salt according to Leslie's.
At the same time that I began getting wildly different readings from Leslie's, they began using a color wheel, which is read by a computer. When I asked Leslie's employees about the difference, they said Phoenix water is less hard now, something about the water source. It sounded like gibberish to me., so I checked with our local City water people, and they gave me the nearest location reading for total hardness that they have for the tap water. But their numbers include magnesium hardness, so they were getting about 200 on the total hardness in my area. I got a CH reading of 175 on the tap water that year with the Taylor reagents. The water quality guy at the City thought my numbers were probably more in line with what was actually going on. I'd agree except for this latest test with the digital probe that's read by a computer. Are reagents still the go-to for chemists as the most reliable method?
Thoughts? Should I use my numbers or go with the digital probe when calculating LSI?
Thanks.
