2.5" x 14" Freshwater RO Replacement Membrane

RO water starting to taste flat or salty? TDS meter creeping up? Production down even with fresh pre-filters? Those are the signs of a tired membrane element, the one part of a reverse osmosis system that actually separates dissolved salts and minerals from your water.

The Crystal Quest 2.5" x 14" Freshwater Reverse Osmosis Membrane (CQE-RC-04111, the 2514 element size) is the replacement element listed for the 300 GPD Crystal Quest Whole House Reverse Osmosis System and the 200 GPD Low-Flow Reverse Osmosis System. Because 2514 is a standard element size, it also fits other RO systems built for 2.5 x 14 inch membranes. It is a thin-film composite (TFC) element for municipal and well water that has been pre-filtered and dechlorinated.

At a glance

The exact element for your system: one per 300 GPD Whole House RO and one per 200 GPD Low-Flow RO
Rejection with its test conditions: 99% nominal salt rejection (96% minimum) at 550 ppm feed, 150 psi, 77°F (25°C) and 15% recovery
Freshwater class: for tap and well water under 2,000 ppm TDS
Long service life: plan on 2 to 3 years; actual life depends on feed water quality, system configuration and usage

What you are looking at

A spiral-wound cylinder. Leaves of TFC membrane are wound around a perforated center tube, with a mesh feed spacer between them to hold a flow channel open. Purified water (permeate) spirals inward and exits through the center tube; everything held back leaves the far end as concentrate. A brine seal on one end seals the element to the housing wall so all feed water passes through it, not around it. It ships in preservative solution with protectors on each end of the permeate tube. The 14" length fits only housings built for it; it is not interchangeable with 2.5" x 21" or 2.5" x 40" elements.

How a reverse osmosis membrane works

Pressure reverses osmosis

Water naturally moves across a semipermeable membrane toward the saltier side. An RO system pushes harder than that osmotic pull, forcing water molecules through the membrane while dissolved ions stay behind. Crystal Quest rates its whole house RO elements at 150 psi operating pressure.

Cross-flow keeps it clean

An RO element does not store what it removes. Feed water sweeps across the membrane and the concentrate carries rejected minerals to drain, which is why one element can run for years. It is also why every Crystal Quest RO system sends about 1 gallon to drain for every 1 to 3 gallons of purified water, depending on your water and settings.

Reading the numbers

Rejection is feed TDS minus product TDS, divided by feed TDS. Element ratings use a single element at 15% recovery so elements compare on equal terms. Colder or higher-TDS water lowers production, and RO water reads 1 to 2 pH points below the feed, because dissolved carbon dioxide passes while buffering minerals do not.

What it reduces

Primary target: total dissolved solids, the sodium, chloride, sulfate, calcium and magnesium ions behind salty or mineral taste and spotting. Crystal Quest whole house RO systems are rated for 96% minimum and 98.5% nominal salt rejection.

Also held back: particles that reach the membrane, including microplastics, are far larger than anything it lets through. The pre-filters take most of them first.

Not designed to handle: free chlorine, which attacks the TFC layer (0.1 ppm maximum); sediment, which belongs to the pre-filters; and iron or manganese above 0.05 ppm or hardness above your system's limit, which foul and scale the surface. Pre-treat these first, or ask us about a Whole House Reverse Osmosis System sized from your water test.

Why Crystal Quest

Matched to our own systems, straight from our replacement tables, with no cross-reference guessing.
Numbers you can check: rejection with its test conditions, and full operating limits in the Specifications tab.
Over 1,000,000 people served since 1994. Crystal Quest builds under ISO 9001 quality management, has made water filtration in the USA for over 30 years and offers lifetime support by phone, email or chat.

Where it fits

300 GPD Whole House Reverse Osmosis System: one element.
200 GPD Low-Flow Reverse Osmosis System: one element.
Not this element: the 400 GPD Whole House RO uses the 2.5" x 21" Freshwater Reverse Osmosis Membrane.

Check the part number on your current element first. RO membranes and filter cartridges are not returnable under our refund policy, so call us if you are unsure and we will confirm the part.

Standard 2514 format

This is a low-energy freshwater element in the standard 2514 (2.5" x 14") format used in 2.5" membrane housings built for 14" elements, including Crystal Quest systems. Crystal Quest rates its whole house RO elements at 150 psi operating pressure, well below what brackish water and seawater elements are built for, so the pump does less work on tap and well water. A shared format name is a good start, not a guarantee: if your system is not a Crystal Quest model, compare the brine seal position, permeate tube ends and flow direction with your current element, or contact us before ordering.

Storage and handling

Each element ships sealed in its bag in a preservative solution. Keep it sealed until you are ready to install it, store it indoors out of direct sunlight, and never let it freeze. Once an element has been installed and wetted, do not let it dry out. If your system will sit idle for a season, Membrane Preservative is used to protect the elements against damage from bacterial growth.

Common questions

Which systems use the 2.5" x 14" element?

The 300 GPD Whole House Reverse Osmosis System and the 200 GPD Low-Flow Reverse Osmosis System each use one.

Is it interchangeable with the 2.5" x 21" element?

No. The 400 GPD Whole House RO System uses the longer 2.5" x 21" element. Order the length your system lists.

How often should I replace a 2514 RO membrane?

Plan on every 2 to 3 years. Actual life depends on feed water quality, system configuration and usage. Track feed and RO water TDS so you replace it when performance drops, not on guesswork.

What salt rejection should I expect?

The element is rated for 99% nominal salt rejection (96% minimum) at 550 ppm feed, 150 psi, 77°F and 15% recovery. Your own reading will vary with your water's TDS, temperature and pressure.

Do I need to flush a new element?

Yes. New elements ship in a preservative solution. Flush for at least 1 hour and discard all permeate and concentrate made during the flush.

Can chlorinated city water go straight to the membrane?

No. The thin-film membrane tolerates no more than 0.1 ppm free chlorine, so the carbon block and SMART pre-filters must remove chlorine first. Change them on schedule to protect the element.

Is it suitable for brackish water or seawater?

This is a freshwater element. Crystal Quest sells brackish water and seawater desal elements as separate products; ask Crystal Quest which class your feed water needs.

Specifications for your selection

Single

SKU: CQE-RC-04111
Diameter (width): 2.5 in
Length (height): 14.0 in
Replace every: 2 to 3 years

Membrane type: Thin-film composite (TFC) reverse osmosis element
Application: Freshwater
Element size: 2.5" x 14"
Part number: CQE-RC-04111
Listed replacement for: 300 GPD Whole House Reverse Osmosis System (1); 200 GPD Low-Flow Reverse Osmosis System (1)
Feed water: Pre-filtered and dechlorinated; free chlorine 0.1 ppm maximum
Rated production: 225 GPD at 150 psi, 550 ppm feed, 77°F (25°C), 15% recovery; actual output drops with colder or saltier water
Nominal salt rejection: 99% (96% minimum) at 550 ppm feed, 150 psi, 77°F (25°C), 15% recovery
Crystal Quest field results: Crystal Quest tests these elements before they ship. At normal line water temperatures they produce 300 GPD or more.
Operating pressure: Rated maximum: 600 psi; suggested operating range: 100 to 150 psi
Pressure note: 600 psi is the element's structural limit; low energy elements are designed to make their rated flow at about 150 psi
Start-up: Flush at least 1 hour; discard all permeate and concentrate from the flush
Replacement interval: 2 to 3 years; actual life depends on feed water quality, system configuration and usage
Format: Standard 2514 element; compare brine seal position and tube ends if your system is not a Crystal Quest model
Storage: Keep sealed until installation, out of direct sunlight; do not let it freeze, and do not let an installed element dry out

Performance curves

Rated 225 GPD at 77°F (25°C), 150 psi, 550 ppm feed.

Figure 1. Permeate flow vs feed temperature at 100, 125 and 150 psi, normalized to the rated flow at 77°F (25°C) and 150 psi.

Data for Figure 1

Expected permeate flow in GPD by feed temperature and feed pressure
Feed temperature	100 psi	125 psi	150 psi
40°F (4°C)	69	88	106
50°F (10°C)	85	108	131
60°F (16°C)	105	133	161
70°F (21°C)	128	162	197
77°F (25°C)	146	186	225
85°F (29°C)	166	211	256
95°F (35°C)	195	247	300

Values in GPD (gallons per day).

Figure 2. Permeate flow vs feed pressure at 50, 60 and 77°F. Flow follows net driving pressure, the feed pressure minus the feed's osmotic pressure (about 7 psi for the 550 ppm test feed). Shaded: suggested operating range, 100 to 150 psi.

Data for Figure 2

Expected permeate flow in GPD by feed pressure and feed temperature
Feed pressure	50°F (10°C)	60°F (16°C)	77°F (25°C)
25 psi	16	20	28
50 psi	39	48	67
75 psi	62	77	107
100 psi	85	105	146
125 psi	108	133	186
150 psi	131	161	225

Values in GPD (gallons per day).

Crystal Quest engineering data. Typical values calculated from the element's rated output at standard test conditions; actual output depends on feed water, recovery and element condition.

Element specifications

Specification	Value
Membrane type	Thin-film composite (TFC) reverse osmosis element
Application	Freshwater
Element size	2.5" x 14"
Part number	CQE-RC-04111
Listed replacement for	300 GPD Whole House Reverse Osmosis System (1); 200 GPD Low-Flow Reverse Osmosis System (1)
Feed water	Pre-filtered and dechlorinated; free chlorine 0.1 ppm maximum
Start-up	Flush at least 1 hour; discard all permeate and concentrate from the flush
Service life	2 to 3 years*

Element performance

Rated production	225 GPD at 150 psi, 550 ppm feed, 77°F (25°C), 15% recovery; actual output drops with colder or saltier water
Crystal Quest field results	Crystal Quest tests these elements before they ship. At normal line water temperatures they produce 300 GPD or more.
Nominal salt rejection	99% (96% minimum)
Test conditions	550 ppm feed, 150 psi, 77°F (25°C), 15% recovery
Operating pressure	Rated maximum: 600 psi; suggested operating range: 100 to 150 psi
Maximum temperature	113°F (45°C)
pH range	Rated 2 to 11; suggested 5 to 11 for continuous operation; cleaning 2 to 12
Free chlorine tolerance	0.1 ppm maximum. Remove chlorine and chloramine before the membrane with carbon pre-filtration (Crystal Quest whole house RO systems include this).
Maximum turbidity	1 NTU
Silt density index	Less than 5 SDI

Feed water limits for the system

Total dissolved solids	Under 2,000 ppm
Hardness	Under 15 gpg
Iron and manganese	Under 0.05 ppm each
Silica and organics	Under 1 ppm each
Free chlorine	None (remove upstream)
Feed temperature	40°F to 105°F

*Service life is an estimate. Actual life depends on feed water quality, system configuration and usage. Performance figures are from the Crystal Quest whole house RO manuals; production falls with colder or higher-TDS water. Element ratings are from the element data sheet. The 600 psi rating is the element's structural limit. Low energy elements are designed to make their rated flow at about 150 psi.

Illustration of a Crystal Quest freshwater reverse osmosis membrane element

When: plan on every 2 to 3 years; actual life depends on feed water quality, system configuration and usage. On well pre-treated water, rejection usually holds for two to three years while production can slip slightly after the first.
How to tell: compare feed and RO water TDS. Replace when rejection keeps falling, or production stays low after new pre-filters and a flush.
Routine: flush the system weekly and log pressures, flows and TDS.
Protect it: change pre-filters typically every 12 to 24 months, about 18 months for most homes, and yearly on chlorinated city water. The 200/300 GPD Whole House RO Filter Pack holds all three.

How to replace it

With the system shut down, remove the end caps from the top of the membrane housings (snap ring or clamp bolts, depending on the housing).
Pull the used element out of the top of the housing; heavy-duty or channel-lock pliers may be needed.
Open the new element bag close to the seal, then remove the element and the core tube protectors from each end.
Inspect the brine seal and permeate tube for nicks or cuts, and replace damaged O-rings or brine seals.
Lubricate the brine seal with a food-grade lubricant and install the brine seal end first, following the housing flow direction.
Insert the element at a slight angle with a slow twisting motion so the brine seal stays in its groove, and push it fully into the housing.
Refit the end caps without pinching the O-rings, reinstall the snap ring or clamp, and reconnect any fittings.
Flush the new element for at least 1 hour, discarding all permeate and concentrate, then return the system to service as its manual directs.

Never miss a change. Choose Subscribe and Save above for 7% off on the schedule you choose, and add the matching filter pack so the whole system is renewed together.

Listed as the replacement membrane (CQE-RC-04111) for the 300 GPD Crystal Quest Whole House Reverse Osmosis System and the 200 GPD Low-Flow Reverse Osmosis System, one element in each.

Match the element diameter, length and application class to your system's replacement list. The 400 GPD Whole House RO System and the 300 GPD Low-Flow RO System use the longer 2.5" x 21" element instead.