Residential RO Elements (NSF58)

Residential RO Membrane Elements, Custom & OEM Spiral-Wound Elements

The heart of any household RO system – that thin film composite spiral wound thing doing all the work inside is the Residential RO Membrane Element. We make those ourselves. At Blue Membrane we cast our membrane and wind our elements here at our facility in GPD ranges from 50-1600 GPD and full customization of size as well as OEM/ODM Private Label.

SPECIFICATIONS MATRIX

50–1600 GPD
35–90 mm diameter
Fits 1812 / 2012 / 2512 / 3012
Spiral-wound polyamide TFC
OEM / ODM & private label

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What’s a residential RO membrane element?

The replaceable spiral-wound cartridge in your point-of-use RO is the heart of your water purifier; its job is to extract contaminants and dissolved salts from your feed water. These elements are manufactured by winding a polyamide TFC (thin-film composite) membrane onto a core permeate tube, and they’re usually rated according to the GPD (gallons per day) output they produce. In your typical home system, typically 50-100 GPD, that one piece alone decides rejection rate, water flavor and how frequently you should replace filters.

Two outcomes that separate us from rebranders

Manufacturer-direct

We make the membrane sheet and wind the element in-house, so batch consistency, dimensions and private-label are all under one roof.
NSF/ANSI 58-ready material set

Built from wetted materials engineered to meet NSF/ANSI 58 performance and NSF/ANSI 372 lead-content requirements.

NSF/ANSI 58

50–1600 GPD

Flux range: 50–1600 GPD
Diameter: 35–90 mm
Length: 180–333 mm
Dimensional tolerance: ≤ ±0.5 mm
Membrane: Polyamide TFC, spiral-wound
Stabilized NaCl rejection: up to 99.5–99.6%*

*Stabilized rejection measured at stated test conditions — see “Rated vs Real-World” below.

Why Most “RO Membrane Suppliers” Don’t Make Their Own Elements

Most of the firms selling “RO membrane elements” have no capability to produce their own element. They purchased the flat-sheet membrane, then put it into their own housings, and print a label. So, batch consistencies, element size, lead time couldn’t be ensured.

That’s what leads to fake “Filmtec” membranes in circulation and to a scan-to-verify app sent out by Dow, or customers opening a new, allegedly real element only to discover a 30-50 TDS reading. Without the factory backing the label, you just get what shows up in the container.

Experienced buyers learn to ask the seller for their certificate and verify the hologram before trusting a marketplace membrane, friction you avoid entirely when you buy direct from the maker.

Factory Note

“Everybody can put a label on. I can take you out to the sheet cutting station and the winder, the vacuum-integrity test benches all components pass prior to boxing. That is the very nature of direct purchasing.”

— Blue Membrane Engineering Team

Manufacturer-Direct vs Rebrander — what actually differs

Capability	Rebrander / distributor	Blue Membrane (manufacturer-direct)
Membrane sheet casting	Bought in	In-house
Element winding & curing	Outsourced / re-spooled	In-house, 8-step line
Custom diameter / length	Catalog SKUs only	35–90 mm / 180–333 mm
Private-label OEM/ODM	Sometimes	Standard (logo, packaging, seals)
Batch traceability	Container-dependent	Per-batch vacuum-integrity QC
Counterfeit risk	High on open marketplaces	None — direct from the maker

Blue Membrane is on the manufacturing side of that line. The same in-house sequence runs in every unit, meaning that the batch that you ordered for month nine is the exact same thing as the sample that you signed off for in month one.

STEP 01

Membrane Sheet Cutting

RO membrane sheet cut

STEP 02

Rolling Machine

Element winding

STEP 03

High-Temp Curing

High-temperature curing

STEP 04

Y-Ring + Packaging

Y-ring seal & pack

The reason is structural: an unknown, inconsistent supply chain is a risk you inherit, whereas buying from the maker gives you one accountable source. Blue Membrane delivers every element from the same line, engineered to the same spec.

Where the element sits in residential filtration systems

This reverse osmosis membrane element constitutes the final high-rejection stage in the multi-step filtration train. Downstream from sediment and carbon filters it fits inside the membrane housing, from where it supplies the storage tank with the treated and pressurised water.

The pre treatment stage – sediment and carbon block – do the dirty job, remove chlorine prior to reaching the RO membrane.
The RO membrane element in RO stage provides fine filtration and high rejection for dissolved salts that are out of reach for UF/NF.
The water exits after the membrane housing, in post treatment, this could be remineralisation, or a polishing filter.

Getting this order right protects membrane life: in any water treatment train, a reverse osmosis system is only as good as the pretreatment feeding the element, so we advise on the entire filtration system, not just the cartridge.

Request a manufacturing & QC overview (with a sample) →

BLUE MEMBRANE RESIDENTIAL RO MEMBRANE ELEMENT RANGE, MODELS, GPD & DIMENSIONS

Our residential line offers nine standard sizes as well as full custom. Elements are named per industry convention for element form-factors: first two digits are the inch diameter of the membrane element; the second two digits are the inch length of the element - so a 1812 is 1.8 inches diameter and 12 inches long.

Get the reverse osmosis membrane element size wrong and it either won't seat in the housing or underperforms - an expensive return for an integrator. Rebranders keep only a handful of catalog SKUs; because we wind every diameter in-house to a tight ±0.5 mm tolerance, the size you need is a line-setup change, not a special order.

RESIDENTIAL RO ELEMENTS

±0.5mm TOLERANCE

MODEL	NOMINAL SIZE	RATED GPD	TYPICAL FIT / APPLICATION
RE-1812-75	1.8″ × 12″	75	Under-sink home RO (most common)
RE-1812-100	1.8″ × 12″	100	Higher-flow under-sink
RE-2012-100	2.0″ × 12″	100	Under-sink / small point-of-use
RE-2012-150	2.0″ × 12″	150	Whole-home booster / light commercial
RE-2512-200/300	2.5″ × 12″	200–300	Light commercial, cafes, labs
RE-2812-400	2.8″ × 12″	400	Light commercial / kiosks
RE-3012-500	3.0″ × 12″	500	Small commercial systems
RE-3013-600/800	3.0″ × 13″	600–800	Commercial point-of-entry
RE-3313-1000/1200	3.3″ × 13″	1000–1200	Small-system / OEM integration

Residential RO Element Selection Matrix

Select a starting model based on its intended application and estimated throughput, then check if its size fits your current housing.

DAILY DEMAND	BEST-FIT HOUSEHOLD / USE	RECOMMENDED GPD	MODEL
Low (1–3 people)	Under-sink drinking water	50–75	RE-1812-75
Medium (3–5 people)	Under-sink, higher draw	75–100	RE-1812-100 / RE-2012-100
High (large family)	Whole-home booster	150	RE-2012-150
Light commercial	Cafe / office / lab	200–400	RE-2512-300 / RE-2812-400
Commercial POE	Small system builder	500–800	RE-3012-500 / RE-3013-800
OEM integration	System manufacturer	1000–1600	RE-3313-1200 / custom

Custom manufacturing for specialized systems

In addition to our stocked line of SKUs, we custom manufacture 50 to 1600 GPD membranes with 35 to 90mm diameter and 180 to 333mm length - all with our tight 0.5mm tolerances - with choice of endcaps and seals (stock or custom).

→ Get the GPD Sizing Selector for your system

Rated vs Real-World GPD, Reading an RO Membrane Element Spec Sheet Honestly

Honesty problem #2: the GPD figure. A "75 GPD" element rating was done at 77°F, 60 psig pressure, low-concentration water, and a recovery rate of 15%. Conditions which no kitchen ever replicates.

This same 75 GPD element will produce only about 16 GPD at 55°F and 30 psig effective pressure - a value that's approximately 21% of its nameplate rating. Actual output can range from a low of about 20% to as high as 40% of label value depending on line pressure and temperature.

Counter-intuitive, but true

The bigger the GPD, the better the water - this is untrue. Based on real world tests, rejecting 99% at 75GPD reduces to 97% at 50GPD and 98% at 100GPD. Larger GPD elements typically waste more water because of lower recovery percentages.

Why the label and your tap disagree (rated-vs-field derating)

Factor	Lab rating condition	Typical home condition	Effect on output
Temperature	77°F (25°C)	~55°F (13°C)	× ~0.6
Feed pressure	~60 psi	~40–50 psi (minus tank back-pressure)	× ~0.5–0.7
Feed TDS / osmotic load	250 ppm NaCl	Often higher	Lowers net driving pressure
Recovery	15%	15–25% (1:3–1:4 to drain)	Sets drain-flow match

What an honest spec sheet publishes

Blue Membrane includes its test conditions with every rejection or flow specification, because a rejection rate without context is marketing hype, not engineering.

Test-condition-backed rejection (Blue Membrane RO series)

Series	Stabilized NaCl rejection	Stated test conditions
Pure-water (C1/C2)	99.5–99.6%	NaCl 1500–2000 ppm, 150–225 psi, 25°C, pH 7–8
Brackish (Z1/Z2)	99.6–99.7%	-
Seawater (H1/H2)	99.8%	-

Read it correctly

We're stating these high 99.5-99.8% rejections which are measured at high pressure and salinity. A home element at 250 ppm TDS is just like anything else in the industry: about 96-98% normalized rejection. We provide the relevant number for your needs, not the absolute highest.

Practical effect: if you change to a higher GPD element, you'll need a larger-capacity flow restrictor to maintain the same recovery rate. A 50 GPD element usually needs 420-525 mL/min; a 75 GPD requires 525-800 mL/min.

Recovery rate, the number that decides your water waste

A residential element usually achieves 15-25% recovery, or, about 3 to 4 litres of wasted water for every litre of permeate. So paradoxically, using higher-rated elements tends to increase waste, not reduce it.

Whether the element recovers a high percentage of its water is set by the recovery rate (which the restrictor sets) and the available pressure/pump capacity – not by the number on the box.

Request Custom Comparison

What a Residential RO Membrane Element Removes, Contaminant Rejection

It’s not a single rejection figure, but one that varies by contaminant. Below are standard residential TFC ranges; we aren’t trying to mislead you by calling them all 99.99%.

There's a reason integrators pursue that last percentage point of rejection: as reef-keepers put it, for every 2% you increase the membrane's efficiency you roughly double the life of the downstream DI resin, so rejection is a running-cost lever, not a vanity metric.

Typical residential TFC rejection by contaminant class

Contaminant	Typical rejection	Source basis
Total dissolved solids / salt (NaCl)	96–99%	Manufacturer spec (250 ppm test)
Lead	~99% (directional)	Vendor field data
Arsenic (V)	~95%	Vendor field data
Nitrate	~85%	University extension
Fluoride / nitrate / arsenic(III)	44–94%	EPA field study

The honest engineering limit: chlorine

The polyamide TFC membrane is attacked by free chlorine. Performance fails after about 1,000 ppm-hours total exposure; its continuous free-chlorine limit is just under 0.1 ppm.

The membrane can't remove chlorine itself; an activated-carbon prefilter must catch it before it hits the element - up to 95% is removed here. The remaining chlorine oxidizes the polyamide membrane's skin, rejection gradually drops, and the permeate TDS climbs.

Why the three-layer build matters

The rejection is performed by a 0.1- to 0.3-micron polyamide skin, supported by a 40- to 50-micron polysulfone layer, which is backed by a 120- to 150-micron polyester fabric supporting the applied pressure. Feed spacer geometry, a unique patentable design area, determines concentration polarization and fouling-it’s why membrane element engineering is anything but a commodity.

Your source water is every bit as important as the membrane element. For brackish water where the feed water TDS is high, a higher pressure membrane series provides a greater degree of rejection, so we match the membrane to your feed water not sell you one model fits all.

This is also where reverse osmosis technology departs from coarser filtration technologies like UF/MF: where those remove particles and some organics, only a reverse osmosis membrane is capable of rejecting dissolved salts like sodium, nitrates and fluoride to this degree. Among the types of reverse osmosis membranes used residentially, this polyamide composite design - its three-layer ro membrane element structure and reverse osmosis membrane material - is what sets the rejection ceiling.

→ Get Instant Quote

Custom & OEM/ODM Residential RO Elements, From Drawing to Mass Production

Engineering Integrity

A system designer doesn’t need a catalog item. They need an element that fits a particular housing, pump, and brand. We run custom and private label programs as standard practice, not as an accommodation.

Whether you're an OEM system builder matching a 100 GPD element to your own housing or a distributor launching a private-label line, the spec that matters is the one drawn to your feed water, not a catalog average. A trap many buyers fall into is contracting with a “custom” supplier who then outsources the winding, losing control over tolerances and lead times. Because we cast and wind ourselves, we hold a tight ±0.5 mm tolerance and control every step - not like a rebrander simply re-packaging an existing item.

Custom Residential RO Elements engineering mass production

±0.5 mm Tolerance Control

Drawing & requirement confirmation.
Sample build.
Performance testing.
Mass production.

What we customise

We work in a diameter and length envelope between 35-90mm and 180-333mm respectively and provide standard or custom endcaps, standard or custom seals, along with complete private label and packaging.

Because our membrane casting and winding is done under one roof, creating a custom geometry means reconfiguring our own line instead of sourcing from elsewhere.

→ Feasibility Check

NSF/ANSI 58 & Material Compliance
for Residential RO Elements

It's often in the certification language that a supplier either slips up or gets a little creative with the truth. This section explains what the standard addresses and what we claim.

The most significant risk for a buyer lies with a supplier who can present a certificate they haven't earned - just such a claim prompted a December 2024 public notice by NSF. Instead of making claims backed by nothing we can support in an audit, we detail material and performance compliances we can substantiate.

NSF/ANSI 58 vs 61 vs 372 — which standard covers what

Standard	Certifies	Applies to
NSF/ANSI 58	Contaminant reduction, structural integrity, efficiency, material safety	The complete point-of-use RO system
NSF/ANSI 61	That wetted materials don’t leach harmful contaminants	Components (incl. a membrane element)
NSF/ANSI 372	“Lead-free” — ≤0.25% weighted-average lead	Wetted components; folded into 58

Certification scope: NSF/ANSI 58 covers reverse-osmosis drinking-water treatment systems and components. Certification must be verified for the exact model being offered.

What Blue Membrane claims, and won’t

Blue Membrane does not present these residential elements as NSF-certified unless a current, model-specific certificate and public listing are supplied for verification.

That’s a choice. NSF announced in December 2024 that a supplier has made and presented a false NSF certification - the quickest route to alienating an OEM buyer.

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Blue Membrane Residential RO Elements Technical Specification View

Housing Compatibility & Cross-Reference, Fits Standard Residential RO Housings

The element doesn’t perform unless it seats properly in your pressure housing. Blue Membrane elements adhere to the exact same form factors as the existing housing.

An element that seats improperly bypasses flow or seals and may result in leakage, the most common failure reported by integrators. We maintain 0.5mm tolerance and cross-reference against your model number - where another may just hope the ‘standard’ size fits.

Residential RO Elements NSF58 certified spiral-wound membrane element form factor specification

Housing & Form-Factor Compatibility

Form factor	Nominal size	Fits housing ID	Equivalent sizing
1812	1.8″ × 12″	~2.0–2.05″ ID	Under-sink (FilmTec/GE)
2012	2.0″ × 12″	2.0″ class	Under-sink / small POU
2512	2.5″ × 12″	2.5″ class	Light commercial
3012 / 3013	3.0″ × 12–13″	3.0″ class	Commercial POE

Includes a standard Y-ring/brine seal or a custom seal if requested, ensuring an accurate fit with no leakage.
0.5mm tolerance to ensure proper fit without forcing.
Cross-referencing your existing element with your existing model number.

→ Cross-Reference Check

Sourcing Residential RO Elements, MOQ, Lead Time, Samples & Private Label

Finding a reliable RO membrane source is as much a strategic supply decision as a technical one, and a costly mistake to get wrong. When a buyer begins to search for a “75 gpd ro membrane price” or a “single residential ro membrane cost,” they’ll find there is no single number, and no single “best residential ro membrane” either. Instead, the actual price is determined by a handful of easily controlled factors.

MOD-A / PRICING FACTORS

Pricing & sourcing factors (request a quote for your parameters)

Factor	How it moves cost & timing
GPD & form factor	Larger elements use more membrane area per unit
Customisation level	Standard SKU vs custom geometry / end cap / seal
Order volume	Sample and low-volume vs recurring production runs
Private label	Logo, packaging and documentation scope
Feed-water profile	Determines series (pure / brackish) and pretreatment advice

MOD-B / OPERATIONS

Test bench samples available before commitment to volume orders.
All batches tested for vacuum-integrity before packaging.
Our in-house manufacturing capability prevents reliance on third-party winder backlog.
Custom logo, packaging, and housing color options are available, as expected for OEM/ODM partnerships.

While our standard residential membranes can ship immediately, custom solutions require time to design, prototype, and validate through our rigorous draw-sample-test process. Provide us with your order volume and targets for an estimated lead time along with your quote.

→ Request a lead-time estimate for your volume

Residential RO Elements (NSF58) Engineering Tools

Custom built residential RO elements made by the membrane specialists.

Submit your GPD target, house size or a drawing and we'll get back with the appropriate model or a custom feasibility analysis, realistic test conditions and lead-time estimate to produce your volumes.

Request a Quote

Which GPD residential RO membrane element do I need — 50, 75, or 100 GPD?

For most under-sink homes, 75 GPD is the sweet spot, and the RE-1812-75 is our most-ordered residential element for exactly that reason. Counter-intuitively, jumping to 100 GPD can slightly lower rejection and waste more water, so bigger isn't automatically better. Match GPD to your daily demand using the Selection Matrix above, then confirm the physical fit against your existing housing before you order.

Is a 100 GPD membrane better than a 75 GPD one?

Not necessarily. Field data shows rejection often peaks around 75 GPD (~99%) and dips at 100 GPD (~98%), and higher-GPD elements can run lower recovery, more water to drain. Choose GPD for your demand, not for the biggest number on the box.

How do I know a low-cost membrane isn’t a counterfeit or a nanofilter mislabeled as RO?

On open marketplaces you often can’t, counterfeit “Filmtec” elements and mislabeled nanofilters are a known problem. Buying manufacturer-direct removes that risk: you get the maker’s test conditions, per-batch QC records, and a traceable element instead of a re-boxed unknown.

Can you manufacture custom sizes, end caps, or private-label (OEM/ODM) elements?

Yes — 50–1600 GPD, 35–90 mm diameter, custom end caps, seals and full private-label packaging.

Will your residential RO element fit my existing RO housing (1812 / 2012)?

Standard 1812, 2012, 2512 and 3012/3013 elements fit the matching standard housings, held to ≤ ±0.5 mm so they seat without forcing. Send us your current model number and we confirm the cross-reference before you order.

Are Blue Membrane residential RO elements NSF/ANSI 58 compliant?

They are manufactured with materials engineered to meet NSF/ANSI 58 performance and NSF/ANSI 372 lead-content requirements. Here is the nuance most suppliers skip: NSF/ANSI 58 certifies a complete RO system, not a standalone replacement element, which instead earns its safety credentials through NSF/ANSI 61 and 372 at the component level. So we describe material and performance compliance honestly, rather than displaying a certification mark we do not hold for the bare element.

Why is my real-world output lower than the rated GPD?

Ratings are measured at 77°F and ~60 psi, but a real kitchen is colder and lower-pressure, so actual output is commonly around 25% of the label.

What is your MOQ and lead time, and how long does an element last?

Samples are available for validation, and standard elements move faster than custom developments, request a quote for an estimate on your volume. A residential element typically lasts 2–3 years, but replacement is condition-driven: monitor TDS-rejection decline rather than the calendar, and good pretreatment extends life.