Each test was accurate and reliable.

The test works, as described in many reviews, really very reliable. Also re-measurements still showed the same value. So reliability is given. (Give droplets in the tested 5ml water until the color changes from red to green) The operation was already often described.
So why my review?
I use a Britta filter and a not exactly cheap coffee machine, which is also equipped with a filter system. In the meantime many household appliances, must be determined and entered before Erstbetriebnahme of water hardness. This indicator is on value 1-4 limited (as with a test strip).
If I now have to enter 7 droplets until the color changes, the value I have to assign each machine?

From Google and possibly for one or the other interesting.:
Droplets 1-7 = German Degrees = soft water = hardness range 1
7-14 drops = degrees German hardness = moderately hard water hardness range 2 =
Droplets> 14 = German Degrees = hard water = hardness range 3
Droplets> 21 = German Degrees = very hard water = hardness range 4

The specification of the hardness range (1-4) is the new scheme. It measures the CaCO3 mmol / 1 (millimoles of calcium carbonate / liter).
The droplet method has proven to be very reliable out and is also less expensive than the 5 test strips. Decimal places are in private households rather less common. To check the filter system and then change only when it needs to be and, of course, the reliability, makes this product for me not only indispensable but convinced. Therefore, full 5 stars.