Teach you how to identify the water quality of the water purifier_lg fridge water filter kit

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Teach you how to identify the water quality of the water purifier

Views : 2 Update time : 2022-02-14 15:48:06 Friends who have a demand for drinking water quality at home often see the TDS test pen when choosing a water purifier. The displayed value is often one of the criteria for judging the water quality of the water purifier.

Where exactly is TDS sacred? How do some water purifiers make the TDS value of tap water from a few hundred to double or single digits?

TDS is the abbreviation of total dissolved solids, which is "total dissolved solids". The measuring tool is the pen-shaped TDS tester that we often see in evaluation and promotion.
Here we will find a bug: the value displayed by the TDS meter is the total amount of solid matter dissolved in the water.

In fact, there are many kinds of solid substances in tap water, such as minerals and trace elements, calcium and magnesium salts that are easy to form scale, sediment dissolved in water, scale and rust that are peeled off from transportation pipelines.

The complexity of solid types makes TDS meters unable to accurately identify whether their composition is beneficial or harmful to the human body.

For example, the TDS value of tap water we use daily is around 100-200, and the TDS value of mineral water sold in supermarkets is also around 100, but mineral water can be directly drunk, but tap water is not.

Such a situation will inevitably be confusing. What is the significance of the water purifier testing TDS value? However, before further explaining this question, let's take a look at the numerical requirements of the national standard for the quality of tap water.

According to the description of the limit requirements for the TDS value of drinking tap water in my country's 2006 "Drinking Water Sanitation Standards": the TDS value of residential water needs to be less than or equal to 1000mg/L.

What kind of numerical concept is this? Generally, the TDS value of tap water in new-style residential buildings is 100-200, and the TDS value of tap water in older residential buildings will not exceed 500.
Generally speaking, as long as the urban water supply is not affected by various disasters, the daily drinking water will basically not exceed this limit.

However, this tap water quality requirement does not meet the direct drinking water standard. We have been taught by our parents to boil water before drinking, and we do not have the habit of drinking tap water directly.

Moreover, the cost of direct drinking water from the factory is quite high, and there is also the problem of secondary pollution during transportation, which is not only unnecessary, but also difficult to achieve.

With the development of life, people will more or less have certain requirements for the quality of tap water, not necessarily for direct drinking, but also to remove impurities, odors, or eliminate scale in the water. At this time, it also reflects the water purifier. existence value.

Back to the question at the beginning, why does the water purifier evaluation show the TDS value of water quality?

The answer is very simple, to show the ultra-high filtration capacity of the water purifier, because it is difficult to distinguish whether the solids in the water are good or bad, it is better to filter them all in one breath. There are no impurities in the water, so it can be directly consumed.

To achieve such a strong filtration capacity, only RO reverse osmosis water purifier can do it.

This type of water purifier can fully filter all impurities including bacteria, viruses and microorganisms in the water through the RO reverse osmosis membrane with a filtration accuracy of 0.0001 microns. Only water molecules and a very small amount of trace elements can pass through. The naturally produced water TDS The value has only single digits.

In addition to reverse osmosis water purifiers, there is also an ultrafiltration water purifier that is common on the market.

This type of product can only simply filter tap water to remove large particles of impurities such as sediment and rust and eliminate odors, while bacteria, viruses, scale, etc. will still remain in the produced water. Such products cannot pass the TDS test to judge the water quality standard.

Smart brand owners will not introduce the specific differences of such water purifiers to consumers in detail. Common reverse osmosis water purifiers will use "pure water" and "straight drinking" as publicity, while ultrafiltration water purifiers will Promote "no power consumption" and "mineral water" as features.

So when buying a water purifier, is it a no-brainer to choose reverse osmosis? Or choose ultrafiltration to drink "mineral water"? Let's analyze it for you:

Reverse osmosis water purifier:

Advantages: The filtration effect is excellent, and the purified water produced can be directly consumed.


1. The reverse osmosis water purifier will produce waste water

2. The water purifier pressurizes the water during work, which requires power consumption

3. The general life of the reverse osmosis water purifier filter element is 3 years, and it needs to be replaced when it expires, and the price is higher

Applicable environment: The water quality is hard, and water pollution problems are prone to occur, such as coastal salt tides and areas prone to floods.

Applicable people: There are extremely high requirements for drinking water quality, especially families who need to take care of infants and the frail elderly.

Ultrafiltration water purifier:


1. Can retain minerals in water, suitable for making tea and coffee to enhance the taste

2. Installation and use, no need to use electricity

3. The filter element of some products can be reused, and the replacement price is lower

Disadvantages: Tap water can only be simply filtered, and it needs to be boiled for drinking, which will cause scale.

Applicable environment: The tap water has many impurities, the water quality is soft, and it is not easy to cause pollution.

Applicable people: There is no high requirement for water quality, and it only needs to filter impurities and odors at a relatively low cost to meet the needs of families who wash vegetables and cook daily.


Although the TDS meter is a reference to visually display the water quality, it can only reflect the water purification effect of the reverse osmosis water purifier.

As for the common ultrafiltration water purifiers, the indication of the TDS meter is not significant for reference. The simplest and most reliable method is to boil the tap water before drinking. I hope this article can help everyone who is buying a water purifier.
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