Water hardness discrepancy

[gwand]

I measure my water hardness at 200 ppm using the APA kit and also the Sera kit. Both kits are in near agreement. My plumber came by and measured water hardness using his kit and came up with a value of 285 ppm. I’m inclined to believe my test results given that two kits are corroborating. What do you think?

 

[MaloK]

Without knowing the exact test he used for reference, I would be inclined to use "my" results eyes closed.

 

[gwand]

Thanks for your opinion. By the way, the Sera test kit for GH is much easier to use than the API kit. The difference is that the Sara kit uses a very wide test tube. You do not have to cap it after each drop of solution. You just shake the tube and it mixes well. Very convenient.

 

[sharkweek178]

What kind of test did he use? Was it reagents or strips?

 

[gwand]

Reagent

 

[Uberhoust]

Did the plumber actually measure the hardness or did he use a TDS sensor? If he used a TDS sensor I would expect a higher reading.

 

[gwand]

Did the plumber actually measure the hardness or did he use a TDS sensor? If he used a TDS sensor I would expect a higher reading.

Good question. I’m not sure.

 

[hamfistUK]

Did the plumber actually measure the hardness or did he use a TDS sensor? If he used a TDS sensor I would expect a higher reading.

My thoughts exactly. Also, I would expect a TDS somewhere around 285 ppm with a GH of around 200 ppm.

 

[gwand]

I think you nailed it. Thanks.