Experience Pure Hydration with Reverse Osmosis Drinking Water Filter

Gold Standard for water purification Scientifically proven Easy self-replacement cartridges

RO Water filter.

All in One Unit Water Filter

No external pumps, tanks or exposed parts.

Conveniently located under the sink, freeing up precious countertop space.

Innovative front loading design for filter cartridges, easy to replace.

Smallest RO Water Filter

  • Usual RO filters are bulky
  • MAX4 is tankless and space saving
  • Frees up countertop space
  • Hide wires and power point beneath sink

Clean RO Water in Seconds

The latest RO water filter technology:
  • MAX4 produces a jet of instant, clean water.
  • On demand. No need to wait.
  • Good water pressure.

Easy DIY Water Filter Replacement

Patent ZL 200910201739.8

Change your filter at home

Save time making service man appointment

Max out each filter till end of useful life

Step 1:

Lift handle and pull filter out

Step 2:
Push new filter in.

Each filter is fitted with a mircochip that records your volume consumption and life of the individual filter. Change only the filters which are depleted.

Stage 1: Sediment Water Filter

In the first stage, a heavy duty pre filter clears out impurities and sediments from the water. This prolongs the life of the stage 2 and 3 filters. Sediment filters operate efficiently for up to a year.

Stage 2: Chlorine Water Filter

Patent ZL201520326026.5

Patented carbon filter intercepts and removes an extremely high rate of 99.9% of bacteria and chlorides. Odours are eliminated and water taste improves significantly.

Stage 3: Patented RO Water Filter

Patent ZL 200910201739.8

Traditional RO filters have water entering at one end and leaving at the other. These high pressure RO systems usually last no more than a year.

The Max 4 high precision filters can last up to 4 years. They are designed to allow water to stream in from both ends of the filter and be purified through the length of the membrane. This design not only preserves the integrity of the filter for longer, it also improves the entire filtration process.

Highest Water Filter Retention rate

To obtain the cleanest water, all RO water purifiers can retain only a percentage of the water. The more advanced the RO filter, the higher the retention rate.

While other RO water purifiers have a water retention rate of 25%, the AOS RO filter holds the patent for the highest water retention rate of 75%.

Water Filter Replacement Indicator

Light indicator at both hot water faucet and water purifier changes colour to reflect life of the filter, giving you ample time to arrange for filter replacements.

White – Normal
Orange – 5% life
Red – 0% life

Automated Self Cleaning RO Filter

Max 4 auto-cleanser performs a flush through the entire system. It is activated:

  • upon powering up or after a reset
  • for every 30 min of continuous usage
  • for every 72 hours of inactivity

Established in 1874

With over 150 years of water heater innovation, A. O. Smith is the leading producer of water heaters.

Automated factories

A. O. Smith does not outsource manufacturing. They own each of their 21 factories worldwide. The factories are 95% automated for optimal quality control.

AR75 Reverse Osmosis Water Filter (Tank)

AR75 Tank RO Water Filter

High Precision RO drinking water purifier. Suitable for families of 4.

Reverse Osmosis Water Filters

AOS water purifiers use Reverse Osmosis (RO), the top international standard for clean drinking water

RO filters use high precision filtering up to 0.0001 microns.
Most water purifiers in Singapore filter up to 0.001 microns.

PUB uses Reverse Osmosis (RO)

PUB uses RO and ultraviolet (UV) to purify our water.
These are proven, top in range methods for purification.

Find out more about PUB NeWater Technology and how they use Reverse Osmosis to get one of the cleanest water in the world.

RO Water Filters – #1 in USA and China

In places where water purification is essential, RO is always used as 0.0001µ filtration ensures that all trace heavy metals are removed.

RO is the top water purification system used in USA and China.

Water Filter Replacement Indicator

Light indicator at drinking water tap changes colour to reflect life of the individual filters, giving you ample time to arrange for filter replacements.

White/Green– Normal
Orange– 5% life
Red– 0% life

Tips: Water Filter Change

Filter Change
  • After changing filter 1, 2 or 3, let water run from the filter tap for 15 min.
  • Do not let filter tap run over 20 min or this will cause ‘leak protection’ to be activated and system will shut down.

Product Specifications

RO filter 0.0001 micrometers
Rated volume produced7500 liters5000 liters
Filter 1 (1 year) $110
Filter 2 (1 year) $100
Filter 3 (4 years) $280
Size (mm)140 (W) x 430 (H) x 445 (D)260 (W) x 420 (H) x 410 (D)
Power (W)10725
Voltage, Hz220V, 50-60Hz220V, 50-60Hz
Filtration rate1800 ml/min196 ml/min
Water supply pressure (MPa)0.10 – 0.350.10 – 0.35
Weight (kg)15.511.0
Warranty1 year1 year