PSI-021-5RM 5 Stage Re-Mineralizing, Oxygen rich alkalising
- USA made Filters
- USA made Housings
- pH Neutral
- 5 Yr Warranty
Reverse Osmosis 5-Stage System – Alkalising, Re-Mineralising, Oxygen-Rich
The PSI-021-5RM delivers pure RO water, restores beneficial minerals, oxygenates, and balances pH — for great-tasting, health-conscious hydration from a sleek, dedicated faucet. Built around a premium DOW FilmTec membrane with a low ~1:1 waste ratio.
Why Choose This System?
This 5-stage RO pairs high rejection performance with re-mineralising, alkalising, and oxygen-enrichment stages to elevate both quality and taste.
- Advanced 5-stage filtration — includes dedicated alkaliser & re-mineraliser.
- Premium DOW FilmTec membrane — ~300 L/day @ 50 psi with ~1:1 low waste ratio.
- Alkalises & adds minerals — boosts pH and flavour with calcium & magnesium.
- Oxygen-rich output — final stage oxygenation for fresh mouthfeel.
- Compact undersink design — dedicated lead-free faucet included.
- NSF-certified components — meets Australian & international standards.
- Auto shut-off valve — prevents tank overfill and conserves water.
How It Works: 5-Stage Filtration
- Stage 1 — 1-micron sediment (U.S.) removes rust, sand & particulates.
- Stage 2 — Omnipure carbon block (U.S.) reduces chlorine, chemicals & odours (≈37,000 L).
- Stage 3 — DOW FilmTec RO membrane removes ~96–98% fluoride, heavy metals, nitrates & dissolved salts.
- Stage 4 — Omnipure coconut carbon post-filter polishes taste and reduces residual VOCs.
- Stage 5 — Re-mineraliser & alkaliser adds calcium/magnesium, oxygenates, balances pH.
System Specifications & Features
- Housings — QMP-300-HP, NSF-certified; burst rating 575 psi (4000 kPa).
- Operating pressure — minimum 40 psi (280 kPa); optimum ~50 psi (350 kPa).
- Main unit size — ~42 cm (H) × 35 cm (W) × 14 cm (D).
- Installation options — ½″ tee olive, ¾″ dishwasher adapter, or ½″ braided-line flick-mixer adapter.
- DIY-friendly — typical install 30–60 minutes with standard tools.
Connection Types
- ½″ Flick-Mixer Braided Line — most common in modern kitchens. Fit the supplied adapter with the rubber washer, then re-attach the braided hose.
- ¾″ Dishwasher Adapter — use the dishwasher cold-water outlet where no dishwasher is installed.
- ½″ Tee Olive Fitting (Copper) — typical for older homes with separate taps and copper lines.
Storage Tank Options
- Standard — 9 L stainless steel tank (NSF certified).
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Alternative sizes:
- 4.2 L — 33 cm (H) × 20.5 cm ⌀
- 9 L — 39 cm (H) × 24 cm ⌀
- 12 L — 39 cm (H) × 27.5 cm ⌀
Faucet Options
Bundle & save: upgrading your faucet with the system is cheaper than buying it later.
Browse Faucet Range, then select your choice from the Faucet Option dropdown above. Fits most sink/benchtop holes (12–13 mm) and standard thicknesses.
Replacement Cartridges & Maintenance
- Annual cartridge pack (ROCDU-02) — order here.
- RO membrane (~4 years) — order here.
- Re-mineraliser / alkaliser (~2 years) — cartridge or calcite refill.
Additional Information
Cartridge replacement tutorial
Warranty
This PSI 5-stage reverse osmosis system includes a 5-year warranty covering defects in materials and workmanship under normal household use. Built with high-grade components from trusted brands — see full warranty terms for details.
Customer Reviews
Customer Reviews
Love this filter system. Easy to install and beautiful drinking water
After doing a lot of research, I decided on PSI to purchase a RO under sink system. So happy I did. The service both over the phone, and through the website chat function was fantastic. Delivery was quick and easy. The pricing is very competitive and I like that I'm supporting Aussie business! This way, I can have confidence that I'll be able to get correct replacement cartridges when I need them.
Callum responded to my enquiries within an hour on a weekend, and the unit was dispatched promptly as well. The plumber found it easy to install and the quality of the water is great. Despite the remineralisation stage my measured water hardness is only 15 ppm. Excellent value compared to other options on the market.
Brilliant service to provide quality parts for great clean water. We had a new system installed day 1 in our new house after using a PSI reverse osmosis 5 stage filtration in our previous house for years. Cannot recommend it enough.
My son and his wife have just had a baby so purchased one of these to make sure the water they use is the best possible, we have owned ours for years they are brilliant.
