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



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

Products


Regular price $720.00
Regular price $720.00
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Reverse Osmosis Undersink 4-Stage System with Gauges & Monitoring – Premium Water Filtration

The PSI-021-4GM is a premium 4-stage reverse osmosis system with pro-level visibility and control. It combines dual stainless pressure gauges, a TDS monitor, and an onboard membrane flush valve — so you get pure water and instant feedback on performance.

Advanced Features for Peace of Mind

  • Dual pressure gauges — one reads mains pressure; the other reads post-prefilter, pre-membrane pressure. The difference shows prefilter pressure drop, helping you diagnose clogging at a glance.
  • TDS monitoring — check dissolved solids before/after the membrane to confirm purity. (Handheld meter included / built-in display depending on kit selection.)
  • Onboard membrane flush valve — quickly clear deposits to 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).
  • 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 for robust 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; tested to Australian Standard AS3497.
  • Inlet ball valve — WaterMark certified to Australian Standards.

4-Stage Filtration

  • Stage 1 — 1-micron sediment (U.S.) removes dirt, sand, and suspended particles.
  • Stage 2 — Coconut carbon block (Omnipure, U.S.) reduces chlorine & organics (≈37,000 L rating).
  • Stage 3 — DOW FilmTec RO membrane removes ~96–98% fluoride, salts, nitrates, heavy metals, etc.
  • Stage 4 — Coconut carbon post-filter final polish for taste and VOC reduction.
  • Optional — Alkaliser (re-mineraliser) adds minerals and balances pH.

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).
  • 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.
  • ¾″ Dishwasher Adapter — use the dishwasher cold-water outlet where no dishwasher is installed.
  • ½″ Tee Olive Fitting (Copper) — typical for older homes with copper pipes to separate taps.

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 ⌀

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.

Cartridge Replacements

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

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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.