PSI-021-4P-GM 4 Stage Reverse Osmosis Under Sink Premium Model



  • USA Made Cartridges
  • USA Made Housings
  • Gauges & TDS Meter
  • 5 Yr Warranty


Regular price $720.00
Regular price $720.00
Notify Me

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).
  • 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

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


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.

Customer Reviews

Based on 1 review
100%
(1)
0%
(0)
0%
(0)
0%
(0)
0%
(0)
B
Ben R
Amazing water

Totally happy with this water filtration system, the water quality is spot on, no after taste at all, just pure clean water. As I was replacing a different filter system it was very easy to install. I would highly recommend this system to anyone.