TF-100 Question

[Ale_Brewer]

Does anyone know what exactly the TF-100's CH reagents test for?

Is it just calcium (without magnesium)?

Is it total hardness (as CaCO3)?

 

[JVTrain]

It's testing only calcium hardness, as dissolved CaCO3. The R-0010 reagent prevents Magnesium interference.

Extended Test Kit Directions

 

[Ale_Brewer]

Isn't CaCO3 an expression of the concentration of hardness ions in terms of their equivalent value of calcium carbonate? If so, wouldn't that include magnesium ions as well? If this is the case, I don't think this could would give an accurate count of calcium ions alone.