Reverse Osmosis Undersink 4-Stage System with Gauges & Monitoring – Premium Water Filtration
Now proven to reduce PFAS (including PFOA) up to 99.9% when properly maintained.
The PSI-021-4GM is our pro-visibility RO: dual stainless pressure gauges, a TDS monitor, and an onboard membrane flush valve for instant performance feedback and longer membrane life. Built around a genuine DOW FilmTec ~300 L/day membrane and efficient ~1:1 waste ratio, it delivers ultra-clean water with smart, at-a-glance monitoring.
Advanced Features for Peace of Mind
- Dual pressure gauges — mains vs. pre-membrane pressure; the difference shows prefilter pressure drop so you can spot clogging quickly.
- TDS monitoring — compare dissolved solids pre/post membrane to confirm purity. (Handheld meter included)
- Onboard membrane flush valve — clears deposits to help maintain flow and extend membrane life.
What Sets This System Apart?
- Pressure gauges — stainless, oil-filled, pressure-compensating.
- Housings — U.S.-made QMP; burst rated to ~575 psi (≈4000 kPa); tested to AS3497.
- NSF-certified tubing — John Guest (UK) NSF/ANSI 61, rated to ~230 psi (≈1600 kPa).
- Auto shut-off valve — Hydromatic (USA) for long-term reliability.
- Check valve — stainless, U.S.-made backflow protection.
- Fittings — genuine John Guest & Jaco Gripper Series only.
- Faucet — Italian/USA/Taiwan NSF lead-free dedicated tap options.
- Membrane — genuine DOW FilmTec (USA) with serial & hologram.
- Filters — U.S.-made; components to Australian Standards.
- Inlet ball valve — WaterMark certified to Australian Standards.
How It Works: 4-Stage Filtration
- Stage 1 — 1 micron sediment (U.S.) removes dirt, sand and suspended particles.
- Stage 2 — Omnipure coconut carbon block (U.S.) reduces chlorine & organics (≈37,000 L rating) and targets chloramines common in AU town supplies.
- Stage 3 — DOW FilmTec RO membrane (U.S.) removes ~96–98% fluoride, salts, nitrates and heavy metals.
- Stage 4 — Omnipure coconut carbon post-filter (U.S.) final polish for taste and VOC reduction.
- Optional — Remineraliser adds minerals and balances pH for a smoother finish.
PFAS Reduction & Water Quality
Carbon → membrane → carbon is a proven sequence for broad contaminant reduction, including PFAS (e.g., PFOA). Typical Australian town water is ~pH 7–7.5. After the membrane, minerals are very low and pH can drop to ~pH 6; using a remineraliser lifts pH back above 7 for balanced taste.
System Specs
- Minimum pressure — 40 psi (280 kPa); optimal ≈ 50 psi (350 kPa).
- Main unit size — 42 cm (H) × 35 cm (W) × 14 cm (D).
- Waste ratio — ~1:1 with integrated flush.
- Dedicated drinking tap — stylish, lead-free options available.
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 to the adapter’s ½″ male thread. Details/Instructions
- ¾″ Dishwasher Adapter — use the dishwasher cold-water outlet where no dishwasher is installed. Details/Instructions
- ½″ Tee Olive Fitting (Copper) — for older homes with separate taps. Cut 45–50 mm from the ½″ copper line, deburr, install the tee, then proceed with the standard PLV/tubing steps. Details/Instructions
Storage Tank Options
- Standard — 9 L stainless steel tank (NSF certified).
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Optional 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 ⌀
- TANK DATA SHEET
Replacement Cartridges & Maintenance
- Annual filter pack (ROCDU-02) — order here.
- RO membrane (~4 years) — order here.
- Re-mineraliser (~2 years, if fitted) — order here.
Performance Data
The system demonstrates high contaminant removal rates across both inorganic and organic compounds:
Inorganic
- Aluminum 99%
- Arsenic 98%
- Arlum 95%
- Cadmium 95%
- Calcium 98%
- Chromium III 98%
- Copper 90%
- Fluoride 98%
- Iron 98%
- Lead 90%
- Magnesium 98%
- Manganese 90%
- Mercury II 85%
- Nitrate 90%
- Potassium 95%
- Selenium 95%
- Silver 98%
- Sodium 95%
- Strontium 90%
- Sulfate 90%
- Zinc 98%
- Total Dissolved Solids 95%
- Asbestos 99%
Organic
- Chlorine 98%+
- Herbicides 98%+
- Pesticides 98%+
- DDT 98%+
- Endrin 90%+
- Lindane 98%+
- Aldrin 98%+
- Benzene 98%+
- VOCs 98%+
- Atrazine 98%+
- Fluoranthene 98%+
- Phenol 98%+
- Trihalomethanes 98%+
- Toxaphene 98%+
- Dichloromethane 98%+
- Chloroform 98%+
- Trichloroethylene 98%+
- Perchloroethylene 98%+
- Tannic Acid 98%+
- Methoxychlor 98%+
- PCB 98%+
Performance Data Sheets
- Membrane — DATA SHEET
- Sediment — DATA SHEET
- Pre Carbon (Omnipure) — DATA SHEET
- Post Carbon (Omnipure) — DATA SHEET
Warranty
Backed by a 5-year warranty. Built from internationally recognised, premium components and tested for reliability, safety, and performance. Covers defects in materials and workmanship under normal use — see full warranty terms for details.