Xiaomi Mi TDS Pen Review – A Cheap Water Quality Tester

As mentioned in a previous post, I’ve recently purchased a water purifier from A.O. Smith and I needed to find a way to figure out if the system is legit. Carrying out a full test would be too expensive, therefore, I decided to get a TDS pen to get basic information about the water quality. Let’s check it out.

Unboxing & Testing

Features & Performance

The Mi TDS Pen can measure the TDS (Total Dissolved Solids) concentration in water. This is not a complete water analysis but TDS is the most common parameter for water testing. The dissolved solids include any salts, minerals, metals, cations or anions dissolved in water, so the lower amount of these solids, the purer the water. The TDS level is measured in parts per million (ppm) or mg/L. The ideal TDS reading for drinking water should be less than 300ppm.

The Mi TDS Pen is quite easy to use. It includes two button cells already, so it’s ready to use out of the box. You will just need to take the pen cap off, place the head of the pen under water, then the TDS reading will immediately show up on the display.

I tested it with the tap water and purified water in my house and the results seem to be accurate. The tap water has the TDS level of 170 ppm while the purified water is much lower at 14 ppm.

Therefore, I highly recommend the Mi TDS Pen if you want to check water quality or performance of your water purifying system.

Buy Xiaomi Mi TDS Pen on GearBest