Regular price $725.00
Regular price $725.00
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5 stage system with Alkaliser to Ph neutral. American filters & membrane

The Reverse Osmosis Undersink 5 Stage model PSI-021-5RM is a premium low waste 1 to 1 ratio unit featuring the exclusive membrane flushing with a full size re-mineraliser.

It has the Dow Filmtec 300 litre per day TFC membrane and will produce up to 300 litres at 50 psi (350 kpa) but will produce up to 450 litres per day higher pressures. What this means is the system will fill faster than most systems on the market. This system has an auto shut-off device that closes off the in-feed supply when the storage tank has filled.

The re-mineraliser (Alkalizer) which contains crushed Marble and or crushed Limestone, it's primary function is to balance the pH to neutral as reverse osmosis water is slightly acidic as the process removes the calcium from the water which acts as a ph buffer. The material contained in the cartridge is a sedimentary rock which is mostly calcium and magnesium but also contains trace elements of other minerals.

As reverse osmosis removes not only the good a bad minerals in the water it is advised to add some good minerals back to the water. Health experts say that you obtain the minerals that your body needs from your diet. You should not rely on water as a mineral source as there is very little available to the body in water as the minerals are totally dissolved. The re-mineraliser in this system is about balancing the pH more so than the minerals added.

Premium systems now have the lowest waste ratio of all systems on the Australian market, using a Patented combination membrane flushing valve/flow restrictor means the waste ratio is about 50% less waste than other brands, waste ratio is now about 1 to 1.

All components are NSF certified to standards 042, 053 or 058


To view the range of optional faucets click here to view

Key Information on the PSI-021-5RM system-


* Main filter unit - 42cm wide, 42cm high and 14cm Deep.

* Storage tanks - 

                           4.2L - 33cm high and 20.5cm diameter

                           9L - 39cm high and 24cm diameter

                           12L- 39cm high and 27.5cm diameter

                           Click here for tank details. Tanks can either stand up or lay down


*Jaco & John Guest fittings

*Omnipure and Filmtec filters/membrane

*QMP american Made housings (Australian Standards AS3497 with a burst strength of 575psi (4000kpa),NSF/ANSI standard 042 certification. Watermarked

* Stainless Steel storage tank

* Pressure Limiting valve with dual check valves as per plumbing code requirement- AS1357-2 licence no 23133

* NSF certified Calcite/remineraliser material


Running costs/Maintenance-

*Annual replacement set of cartridges- $70 to be replaced every 12months depending on conditions  Annual change re-order

*Membrane replacement every 4 years - $85 Membrane Re-order

*Remineraliser every 24 months - $45 Remineraliser/Calcite reorder

Options when checking out-

Connection fitting option.

This will depend on what style of piping you have underneath your kitchen sink. Generally if the kitchen was build in the last 30 years you will have 1/2" flick mixer braided lines which is the first option. If you would like for the system to draw water from the connection of the dishwasher select 3/4" dishwasher connection. If you have older style piping under the sink with copper piping you will need to select the 1/2" Tee Olive connection. If your not too sure about any of the above connections select all three and you will have all bases covered.

Faucet options

Depending on what style of tap you would want mounted on the kitchen sink for you filtered water to come from. The standard faucet/tap supplied with the system is model "C". You can also select a 3 way mixer tap which will replace the existing kitchen tap so the filtered water and hot/cold water come from the same tap and no need to mount a seperate tap.

Tank size options

This will depend on how much water you would like to have on hand at any one time. Generally a 9L storage tank is enough for up to a family of 5. If the tank was full and you were to take 2 L from the tank it would only take 8 minutes for the system to replace the 2 L and shut itself back down.

Annual sets of cartridges

These will be the most common changed cartridges. You will need to replace these every 12 months so its always handy to have some on hand.


For membrane treatment rates click here. Removes 98% of Fluoride.

Click here to obtain more information about waste ratios

Mains connect systems; click here to view how each are installed water filter parts

Click here for selection Advice


If you option to have the hand held TDS meter with the unit beware that the system will have an elevated reading due to having the reminerliser cartridge.

All reverse osmosis systems require a minimum pressure of 40 psi (280kpa) with 50 psi (350kpa) or more is ideal. If you are unsure what your pressure is check with your local Council or water authority.

maximum infeed tds of 500ppm is required. Medium waste ratio would be required anything above 500ppm.

10 year warranty

Product comes complete, ready for installation.

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