Trivia丨Extend the life of the RO membrane 6 practical tips

Trivia丨Extend the life of the RO membrane 6 practical tips

As the “heart” of the water purifier, the RO membrane directly determines the water quality and the cost of replacing the core (the price of a single unit is usually in the range of 50-120 U.S. dollars). But 90% of users do not know: scientific maintenance can make RO membrane life 1-2 years longer! Today we are from 5 key dimensions, hand in hand to teach you to guard this “water purification engine”.

First, pretreatment is the key: do not let the RO membrane “alone!
RO membrane pore size of only 0.0001 microns, equivalent to one millionth of a hair. If direct contact with untreated raw water: sand and rust will block the membrane surface residual chlorine will oxidize and destroy the polyamide membrane material calcium and magnesium ions are easy to trigger scaling!
✅ Correct practice:
1. Install a three-stage pretreatment system:
The first stage: 5μm PP cotton filter → intercept large particles
Second level: granular activated carbon → adsorption of residual chlorine organic matter
The third level: sintered activated carbon / scale inhibitor → further soften the water quality
2. Northern water hardness > 200mg / L, it is recommended to increase the water softening resin cartridge

Second, regular change “shield”: pre-filter replacement schedule

Experimental data show that: overdue use of the pre-filter will allow the RO membrane pollution rate increased by 3 times. Recommended cycle:

Filter type                               Regular cycle                      Highly polluted water cycle
PP cotton                                3-6m                                        1-2m
Activated carbon                    6--12m                                      3-6m
Scale inhibitor cartridge          12m                                          6m


🔔 Intelligent reminder:
Access APP management
Mark the replacement date on the filter cartridge
Check immediately when TDS value rises by 10%.

Anti “dehydration shock”: shutdown maintenance guide
RO membrane dry for a long time will lead to:
Membrane shrinkage and deformation (loss of more than 20% of water production)
Breeding of stubborn organisms
Membrane salts crystallization

⏰ Response options for different downtime durations:
<3 days: normal use without treatment
3-30 days:
1. Close the water inlet valve
2. Empty the pressure bucket
3. Turn on the water for 10 minutes every 7 days

>30 days:
1. Use special protective fluid (e.g. DOW Fooding fluid)
2. Keep sealed in a cool place


IV. Pressure Balancing Technique: Water Pressure Control Standards
RO membrane ideal working pressure is 0.2-0.4MPa. abnormal pressure will lead to:

Pressure conditions Consequences Solutions
>0.6MPa Membrane surface pressure loss Installation of pressure reducing valve
<0.1MPa Decrease in water yield Add a booster pump
Fluctuation >±10% Joint leakage Installation of pressure stabilizer

📊 Detection method:
1. Connect the pressure gauge to the water inlet end.
2. Record the morning/evening peak pressure value
3. Adjust to green safety zone (0.2-0.4MPa)

V. Deep SPA care: cleaning and disinfection process
Even with proper protection, RO membranes still accumulate about 5-8 g/m2 of contaminants per year. Chemical cleaning is recommended every 6-12 months:

🔧 Four-step cleaning method:
1. Alkaline cleaning (pH=10-12)
Formula: 0.1% NaOH + 0.03% sodium dodecyl sulfate
→ Remove organic pollutants
2. Acidic cleaning (pH=2-4)
Formula: 1% citric acid solution
→ dissolve inorganic salt scale
3.Sterilization
Using 0.1% peroxyacetic acid immersion 30 minutes
4.Performance testing
Record before and after cleaning: water production, desalination rate, differential pressure

Sixth, temperature control: to avoid “hot and cold violence” injury
RO membrane optimal working temperature of 25 ℃ ± 5 ℃. Extreme temperatures can lead to:
Low temperature damage (<5 ℃):
① Decline in water production (every 1 ℃, the water volume decreased by 3%)
② increased risk of membrane embrittlement cracking
Increased risk of diaphragm brittleness and cracking ③ Icing and clogging at the thick water end
High temperature damage (>45℃)
① polyamide layer degumming and blistering
② desalination rate decreased by more than 50%
Accelerated residual chlorine oxidation reaction

✅ Response program:
1. Winter protection:
Installation of pipe insulation cotton (recommended rubber-plastic material)
At night to maintain the lowest level of water production cycle
Installation of instantaneous thermostatic valve (maintain 15 ℃ water temperature)
2. Summer protection:
Avoid direct sunlight on the water purifier (use a light shield)
Discharge cold water for 30 seconds before first use every day
Match with cold water circulation system (e.g. water storage tank + circulation pump)

🌡️ Intelligent Monitoring:
Real-time monitoring of water temperature through IoT probes (Mi Home and other smart home systems)
When the water temperature <10℃ or >35℃ automatically trigger the protection mechanism

Frequently Asked Questions
Q: How to determine the RO membrane needs to be replaced?
→ Replace it immediately when the following conditions occur:
Water production drops by more than 40%
Desalination rate <90% (TDS value doubled)
Performance cannot be restored after cleaning

Q: Is the maintenance cost high?
→ A full set of annual maintenance cost is about $30, but can:
Extend RO membrane life by 1-2 years (save 50-300 USD)
Reduce wastewater ratio to 1:1 (save 50% water)