The ppm value of the mountain spring water flowing out of the Feng Shui dragon vein tested by an ordinary water quality test pen is 150. What is the water quality?

Ordinary water quality test pens should be used to test TDS values. The limit of this value for drinking water is 1000ppm. Theoretically speaking, if it is lower than this value, it is qualified (only refers to a single parameter being qualified).

Water quality cannot be judged purely from one project indicator. Evian mineral water is about 300, Wahaha pure water is less than 5. But we cannot conclude that Wahaha is better than Evian.

The lower the TDS value, the purer the water. The higher the TDS, the higher the dissolved solids in the water, but this does not mean that the water quality is poor. Because dissolved solids can be pollutants, they can also be beneficial trace elements.

In short, using a single TDS value to judge water quality is one-sided.