Hi!
I am a huge water drinker, and I can’t help it. Those around me got used to this habit.
So, in order not to waste a fortune on bottled water, we’ve purchased a water filter. Many filters, to be honest, because the water in my region is horrible due to old pipes plus a few more reasons.
It’s one thing knowing that the water is bad, but actually seeing it is a whole other thing. That’s where a TDS water tester is of help. The brand XiaoMi is great at creating useful little things, that’s why we decided to order their water quality tester.
Appearance:
The packaging is really cute. I would not be embarrassed to give this tester as a present to some fitness chick.
I ordered the tester directly from China, that’s why the instruction was in Chinese, as well as the text on the backside of the box.
Was that a problem? Absolutely not! The tester is really simple and convenient in use.
There is another blue carton box and the device itself. At first, I thought it would be hard to get it out, but...
...the little hole on the other side solved this problem. I love that Xiaomi takes care even of such little things like getting the product out of the box. 
The TDS tester itself looks really impressive. It’s made of glossy white plastic. Its size is comparable to that of a marker pen.
XiaoMi is attentive to details, as always. There is their logo on the battery holder (there is a battery in the kit btw.) The name of the device TDS (Total Dissolved Solids) can be found on the only button.
The cap that protects the electrodes doesn’t slip out of your hands. You don’t have to be afraid of water getting into the device, just make sure that you don’t dip the tester past the button-line (otherwise it can simply drown.)
How does it work?
A TDS meter is basically a electrical charge (EC) meter whereby two electrodes equally spaced apart are inserted into water, and used to measure charge. The result is interpreted by the TDS meter and converted into a ppm figure. If water contains no soluble materials and is pure, it will not conduct a charge and will therefore have a 0 ppm figure. Conversely, if the water is full of dissolved materials, it will conduct a charge, with the resulting ppm figure being proportional to the amount of dissolved solids. This is because all dissolved solids have an electrical charge, which allows conduction of electrical charge between the electrodes.
Best drinking water must be under 50 ppm, regular water between 100 and 300 (not safe to drink). Water with more than 300 ppm must not be used for drinking purposes.
About the results (and why we shouldn’t completely trust them).
Let’s take a look at our tap water!
89? Not bad! Even though this water can be used for drinking purposes, we must remember that it’s not that safe, because the pipes in my apartment are pretty old.
Now a 4 stage water filtration system.
Not much better than tap water, but since my filtration system has an additional ionizer I find it ok.Of course, sometimes there are absolutely no doubts, for example, if XiaoMi tester shows something like 1000 ppm. But in our case, it was clear that tap water isn’t safe even without this device. Why have I spent 20 bucks then?
It’s simple.
1. This tester is of help when you have to control the condition of your water filtration system. If the water quality is getting worse, it means that the filters don’t work properly.
2. It can be useful on trips, if you have to decide whether you should buy bottled water or boil tap water.
3. It will be extremely helpful for fish tank owners, who are concerned about water hardness and impurities affecting exotic aquarium pets. The tester can also help you decide if the tank requires refilling or not.
4. And, of course, the tester will give you the excuse to dip it into any liquid possible, roll your eyes and say : “This water is not soft enough for me!”
Just kidding
