5-Stage Under-Sink RO System

Description

An under-sink RO system is the most practical way to get safe, good-tasting drinking water in an Oman home without buying bottled water every week. This 5-stage unit installs inside the kitchen cabinet, runs to its own dedicated tap, and produces around 100 GPD (roughly 380 litres a day) — far more than a family of four will drink and cook with.

How this 5-stage under-sink RO system works

Municipal and tanker water in Muscat usually arrives with a mix of sediment, residual chlorine and dissolved salts. Each stage handles one part of that problem:

• Stage 1 — 5 micron sediment filter: removes sand, silt and rust picked up from roof tanks and old pipework.
• Stage 2 — granular activated carbon: strips chlorine, taste and odour before they reach the membrane.
• Stage 3 — carbon block: a second polish that catches finer organics and protects membrane life.
• Stage 4 — 100 GPD RO membrane: the working stage. Rejects up to 96–98% of dissolved solids, so a 900 ppm feed typically comes out under 40 ppm.
• Stage 5 — inline post carbon: final taste polish on the way to the tap.

A 3.2 gallon pressurised storage tank keeps treated water ready, so there is no waiting at the tap.

Who this under-sink RO system suits

Apartments, villas and small offices where the priority is clean drinking and cooking water rather than treating the whole building. If you are on high-TDS well water, or you also want mineral re-addition, the 6-stage under-sink RO system adds a mineral cartridge on the outlet. For hard water causing scale in geysers and washing machines, that is a separate job — see our water softeners.

Specifications

• Stages: 5 (sediment, GAC, carbon block, RO membrane, post carbon)
• Membrane output: 100 GPD (~380 L/day)
• Feed TDS range: up to 2,000 ppm
• Feed pressure: 2.1–4.0 bar (booster pump included)
• Power: 220–240 V, 50 Hz, 24 V DC pump
• Tank: 3.2 gallon pressurised, food-grade liner
• Cabinet space needed: approx. 40 x 25 x 45 cm plus tank
• SKU: FARZ-RO-002

What you get with installation

Price includes delivery inside Muscat, professional installation with the dedicated faucet and drain saddle, commissioning, and a TDS test before and after so you can see the result. Cartridges for stages 1, 2, 3 and 5 are changed every 6–12 months depending on your feed water; the membrane typically runs 2–3 years. We carry all replacement cartridges in stock in Muscat, so a service call does not turn into a two-week wait for parts.

The system carries a 1-year warranty on the pump, housings and fittings. Consumable cartridges and the membrane are excluded, as normal.

Why buy an under-sink RO system from us

We test your actual water before quoting. If your TDS is low enough that a simpler carbon setup would do the job, we will tell you that instead of selling you an RO. Where RO is the right answer, we size the membrane and pump to your feed pressure so the unit is not running dry or wasting water. Removing dissolved solids by reverse osmosis is the treatment method the World Health Organization drinking-water guidelines describe for high-salinity supplies, which is exactly the condition across most of the Gulf.

Call or WhatsApp +968 9763 7786 for a free water test and a fixed installed price, or browse the full range of RO systems.

Common questions

How much water does it waste? A standard 100 GPD membrane rejects roughly 3 litres to drain for every 1 litre produced. We can fit a flow restrictor and permeate pump to bring that closer to 1:1 if your water bill matters.

Does RO remove useful minerals? Yes, it removes most of them along with the salts. If you want calcium and magnesium added back, choose the 6-stage version with a mineral cartridge.

Can it be fitted in a rented apartment? Yes. The under-sink RO system connects to the existing cold feed and drain, and the only permanent change is a 12 mm hole in the sink or countertop for the faucet.

How long does installation take? Around 60–90 minutes for a standard kitchen.