Water purifier purchase guide: filtering method advantages and disadvantages of analysis + cartridge role of the whole analysis

As people pay attention to the safety of drinking water, water purifier has become a necessary home appliance for many families. But there are many types of water purifiers on the market, filtering technology varies, how to choose the right water purifier for yourself? What is the role of different cartridges? Today we will comprehensively analyze the water purifier filtration, the role of all levels of cartridges, as well as purchase skills!

First, the common water purifier filtration method and the advantages and disadvantages of comparison
1. PP cotton filtration principle: through the polypropylene fiber (PP cotton) to intercept sediment, rust, suspended matter and other large particles of impurities.
✅ Advantages: low cost, fast filtration speed, suitable for pre-filtration.
❌ Disadvantages: unable to remove bacteria, viruses, heavy metals and other tiny pollutants.
2. Activated carbon filtration principle: using the adsorption capacity of activated carbon to remove residual chlorine, odor, some organic matter
✅ Advantage: improve taste and remove residual chlorine.
❌ Disadvantages: unable to filter heavy metals, bacteria, need to be replaced regularly (otherwise it may breed bacteria)
3. Ultra Filtration (UF) Principle: Uses ultrafiltration membrane (0.01 micron) to filter bacteria, colloid, macromolecule organics and retain minerals.
✅ Advantages: no need to plug in, no waste water, retains beneficial minerals.
❌ Disadvantages: unable to filter viruses, heavy metals, not recommended for use alone in areas with poor water quality.
4. Reverse Osmosis (RO) Principle: Utilizes RO membrane (0.0001 micron) to filter almost all pollutants, including heavy metals, viruses, bacteria.
✅ Advantages: the highest filtration precision, the water is close to pure water, suitable for areas with poor water quality.
❌ Disadvantages: needs to be plugged in, produces wastewater (wastewater ratio 1:1~3:1), filters out minerals (can be supplemented with a post-mineralization cartridge).
5. Nanofiltration (NF) principle: between ultrafiltration and reverse osmosis, can filter some heavy metals and retain some minerals.
✅ Advantages: more energy efficient than RO, retains beneficial minerals.
❌ Disadvantages: filtration capacity is not as good as RO, higher price.


Activated carbon adsorption
Advantages: 1. Low cost, simple maintenance, 2. Effectively improve taste, remove odor and residual chlorine (effective for disinfection by-products of water plants), 3. No need for electricity, does not produce wastewater
Disadvantages: 1, unable to remove heavy metals, scale (calcium and magnesium ions), bacteria and viruses 2, short life (3-6 months to replace the filter), saturation may release pollutants
Applicable scenarios: as a pre-filtration or with other technologies suitable for water quality in good areas

Ultra-filtration (UF)
Advantages: 1, retain minerals (calcium, magnesium, etc.), does not change the acidity or alkalinity of the water 2, no electricity, no waste water, large flow rate, removes most of the bacteria and suspended solids
Disadvantages: 1, can not filter viruses (smaller), heavy metals, scale; 2, need to be rinsed regularly, high hardness areas in the north easy to scale
Scenario: water quality is softer, no heavy metal pollution in the region suitable for daily household water (non-direct drinking)

Nanofiltration (NF)
Advantages: 1, retain beneficial minerals, remove heavy metals; 2, lower wastewater ratio than RO (about 1:0.5), more energy efficient
Disadvantages: 1, high cost, low market penetration; 2, can not completely remove viruses and scale (need to combine with other technologies)
Applicable scenarios: demand for mineral retention and medium water quality areas

UV sterilization
Advantages: 1, instant sterilization, no chemical residue 2, with other filtration technology can improve safety
Disadvantages: 1. only sterilization, not filtering other pollutants (need to match the pre-filter) as an auxiliary technology for medical or special needs 2, the need for regular replacement of lamps, and high requirements for water transparency (turbid water effect of the scene poor results)

Ceramic filtration
Advantages: 1, can be cleaned and reused, long life 2, no electricity, suitable for outdoor emergency
Disadvantages: 1, can not filter viruses, chemical pollutants 2, small flow, easy to clog
Applicable scenes: outdoor travel or as a front coarse filter

Distillation method (distillation filtration)
Advantages: 1, the purification effect is very strong 2, can remove 99.9% of the pollutants, the purity of the water is close to laboratory-grade pure water, better than RO reverse osmosis
Disadvantages: 1, high energy consumption, slow, heating process power consumption is not suitable for large amounts of water 2, special water quality areas: high salinity, high heavy metal pollution or desalination of seawater
Scenarios: 1, laboratory / medical use: the need for ultra-pure water demand scenarios (such as reagent preparation, medical equipment clear 2, the output water for “soft water”, long-term drinking may lack the human body needs calcium, wash) magnesium and other minerals (need to be supplemented through the diet), the taste is bland, part of the user is not accustomed to

Reverse osmosis RO
Advantages: 1, produce waste water (pure water: waste water ≈ 1:1 to 1:3), waste of water resources, the need for electricity, the flow rate is small (need to store water buckets or large flux models) 2, remove all minerals, filtering out minerals (can be supplemented by the rear mineralization cartridge)
Disadvantages: poor water quality, industrial pollution areas or users with high water quality requirements.
Usage scenario: poor water quality, industrial pollution areas or users with high water quality requirements

Second, the role of the water purifier cartridge level and replacement recommendations
Water purifier is not a once-and-for-all investment, but the need for regular maintenance of the system, overdue cartridge is more dangerous than not installing a water purifier, today we come to the depth of analysis of the cartridge overdue service of the five major risks, after reading you will understand: timely replacement of the core is not only the maintenance of the equipment, but also the guardian of the family's health! Different brands of filter life is different, it is recommended to adjust the replacement time according to the water quality and frequency of use.

Filter cartridge level                   
The first level: PP cotton main role: filter sand, rust and other large particles, if not replaced, clogged pores lead to small water flow, intercepted impurities began to release the second, the turbidity of the water does not fall, but instead of rising microorganisms form a “pollutant”, the test shows that the number of bacteria may be exceeded by 10 times; Replacement cycle of 3-6 months!

The second level: activated carbon main role: adsorption of residual chlorine, odor, if not replaced, adsorption saturation residual chlorine removal rate plummeted from 99% to 30%, becoming a fine hotbed, laboratory tests show that over 3 months the total number of bacterial colonies increased by 50 times to start releasing the adsorbed pollutants, resulting in secondary pollution of the water quality Replacement period of 6 - 12 months

The third level: ultrafiltration membrane main role: membrane filament long-term pressure leads to pore size expansion (0.01 micron → 0.02-0.05 micron), bacteria (0.2-5 micron) through the rate of <0.1% to 5-15%; colloidal material retention rate decreased by 40-60% Replacement cycle 1-3 years

The third level: RO membrane main role: core filtration layer (bacteria, heavy metals, etc.) If you do not replace the
Desalination rate from 95% to less than 80%, heavy metal filtration effect is greatly reduced membrane fouling leads to the deterioration of the wastewater ratio from 1:1 to 3:1, wasting water resources TDS value of the effluent may rebound to more than 100 (new membrane is usually < 20) 
Replacement cycle 1-3 years

The fourth level: after the activated carbon main function: improve taste, if not replaced, the loss of taste improvement function, the water may appear odor, carbon powder leakage leads to black particles contaminated drinking water, microbial risk of exceeding the higher than the front activated carbon, replacement cycle: about one year

Third, the common drinking water testing methods
TDS test pen is used to test one of the indicators of water quality, TDS value on behalf of the total dissolved solids in water, the unit is PPM, its measurement principle is actually through the measurement of the conductivity of the water and thus indirectly reflect the TDS value, focusing on testing the purity of potable water, but also one of the lower cost of testing equipment.
TDS represents the amount of soluble solids in water, the higher the TDS value, the more ions, and vice versa, the higher the purity of purity.
xppm: 1 liter of water contains x milligrams of dissolved solids.
0-50 High purity
50-100 High purity
100-300 Average purity
300 - 600 Scaling
600-1000 Poor taste
Above 1000 Unsuitable for drinking
As required by the Water Quality Standards for Drinking Water Purification (C)94-2005).
Regional standard   
Municipal domestic water Total hardness ≤300mg/L
World Health Organization drinking water standard (China reference) Total hardness ≤50mg/L
U.S. drinking water standard Total hardness ≤50mg/L
EU drinking water standards Total hardness ≤70mg/L


Fourth, how to choose the right water purifier?
The core of the water purifier is the cartridge, choose the right to ensure filtration effect and drinking water safety, but there are many types of water purifiers on the market, the price difference is large, how to identify the advantages and disadvantages? Today to popularize the selection criteria, including the type of choice, user needs, water-related approvals, NSF certification and other key indicators to help you avoid the business set!
1. Look at the water quality
Better water quality (TDS<80): ultrafiltration + activated carbon combination can be.
Poor water quality (TDS>100): RO reverse osmosis water purifier is recommended. 2.
2. Look at the demand
High demand for direct drinking → RO reverse osmosis (safest).
Want to retain minerals → ultrafiltration or nanofiltration (best to boil and drink).
Whole house water purification → pre-filter + centralized water purifier + reverse osmosis water purifier.
3. Look at the NSF certification (international authoritative certification)
NSF (National Sanitation Foundation) is an authoritative certification of the water purification industry, through the NSF-certified cartridge is more safe and reliable, no certification of the cartridge may be unqualified materials, filtration effect does not meet the standards of the problem!

4. Look at the water-related approvals (official records)
Water-related approvals (full name: involving drinking water health and safety products health license approvals) is the China Healthcare Commission on the mandatory certification of water purification equipment, equivalent to the “identity card”, in the packaging or instructions to find “Wei Shui Bei Jin word” or “Wei Shui Bei word”. On the package or manual, find “Wei Shui Bei Zi” or “Wei Shui Bei Zi” + number, log on the official website of the Commission (https://slps.wsjk.fujian.gov.cn/) and enter the approval number to check the authenticity.

Suggestions for selection: You must choose the cartridge with formal water-related approvals, otherwise it may be a three-no product, no approval number of the cartridge may use poor quality materials, there is a risk of secondary pollution!

V. Summary
✅ RO reverse osmosis: the most thorough filtration, suitable for poor water quality areas
✅ Ultrafiltration / nanofiltration: retain minerals, suitable for families with good water quality when shopping for a combination of water quality, budget, demand, and attention to the cost of filter replacement, in order to choose the most suitable water purifier!
What type of water purifier is in your home? How is the experience of using it? Welcome to leave a message to share!