Crystal Quest 2.5" x 14" Freshwater RO Membrane, 2514 TFC Element

This 2.5" x 14" RO membrane is the element inside an RO system that does the real separating: it holds back the dissolved salts and minerals while purified water passes through. When your RO water begins to taste salty or flat, the TDS reading keeps creeping upward, or output falls even though the pre-filters are new, a worn membrane is the usual cause.

Crystal Quest lists this Freshwater Reverse Osmosis Membrane (part number CQE-RC-04111, size 2514) as the replacement for its 300 GPD Whole House Reverse Osmosis System as well as its 200 GPD Low-Flow Reverse Osmosis System. Since 2514 is an industry-standard size, the element also suits other RO units designed for a 2.5 by 14 inch membrane. The element uses TFC (thin-film composite) construction and is meant for municipal or well supplies that were pre-filtered and dechlorinated first.

Key features of this 2514 RO membrane

• Made for your system: a 300 GPD Whole House RO takes one, and a 200 GPD Low-Flow RO uses one as well.
• Rejection stated with its conditions: 99% nominal salt rejection, 96% minimum, measured at 550 ppm feed, 150 psi, 77°F (25°C) and 15% recovery.
• Freshwater class: intended for well and tap water below 2,000 ppm TDS.
• Years of service: expect 2 to 3 years, although feed water quality, system setup and household demand decide how long it actually lasts.

How the element is built

The element is a spiral-wound cylinder. Sheets of TFC membrane are wrapped about a perforated tube at the center, and a mesh spacer between the sheets keeps a channel open for the feed water. The purified water (permeate) travels inward in a spiral and leaves via the center tube, while everything that is rejected exits at the opposite end as concentrate.

At one end, a brine seal closes the gap between element and housing wall, so the feed water has to go through the membrane rather than past it. The element is packed in preservative solution, and both ends of the permeate tube are capped with protectors.

The 14" length only fits housings made for that length. It cannot be swapped with 2.5" x 21" or 2.5" x 40" elements.

How RO membranes separate salts from water

Pressure turns osmosis around

Left alone, water crosses a semipermeable membrane toward whichever side holds more salt. A reverse osmosis system applies more force than that natural osmotic pull, which pushes the water molecules across the membrane and leaves the dissolved ions on the feed side. Crystal Quest specifies 150 psi operating pressure for the elements in its whole house RO systems.

Cross-flow keeps the surface clear

Whatever the element rejects is not stored inside it. Feed water flows along the membrane surface, and the concentrate takes the rejected minerals away to the drain, which is how a single element can last for years.

The same principle explains the drain water: each RO system from Crystal Quest sends roughly 1 gallon to drain for each 1 to 3 gallons of purified water. The exact ratio varies with your water and settings.

Understanding the figures

To calculate rejection, subtract the product TDS from the feed TDS and divide the result by the feed TDS. Elements are rated one at a time at 15% recovery, so different elements can be compared fairly.

Production drops when the water is colder or carries more TDS. RO water also measures 1 to 2 pH points lower than the feed water, because dissolved carbon dioxide gets through while the buffering minerals are held back.

What this RO membrane reduces, and what it doesn't

Main target: total dissolved solids, meaning the sodium, chloride, sulfate, calcium and magnesium ions that cause salty or mineral flavors and spotting. The whole house RO systems from Crystal Quest carry a rating of 98.5% nominal and 96% minimum salt rejection.

Also stopped: any particles that make it to the membrane, microplastics included, are much bigger than what can pass through it. Most of them are caught earlier by the pre-filters.

Not built for:

• Free chlorine, which damages the TFC layer (0.1 ppm maximum)
• Sediment, which is the pre-filters' job
• Iron or manganese above 0.05 ppm, or hardness above what your system allows; these coat and scale the membrane surface

Treat these before the water reaches the membrane, or choose a Whole House Reverse Osmosis System that is sized to your water test.

About Crystal Quest

• Taken from Crystal Quest's own replacement tables, so it matches their systems without any cross-referencing.
• Figures you can verify: the rejection rate is published along with the test conditions, and the Specifications tab lists all operating limits.
• In business since 1994, with more than 1,000,000 people served. Crystal Quest works to ISO 9001 quality management and has been building water filters in America for more than three decades.

Where it fits

• 300 GPD Whole House Reverse Osmosis System: takes one element.
• 200 GPD Low-Flow Reverse Osmosis System: takes one element.
• Different element needed: the 400 GPD Whole House RO takes the 2.5" x 21" Freshwater Reverse Osmosis Membrane instead.

Before you order, compare the part number on the element you are replacing. RO cartridges and membranes can't be sent back, which is why you should get in touch if you are not sure which part you need.

The standard 2514 format

This low-energy freshwater element uses the common 2514 (2.5" x 14") size found in 2.5" membrane housings designed for 14" elements, Crystal Quest systems among them. Crystal Quest operates the elements in its whole house systems at 150 psi, far less than brackish and seawater elements are designed for, so on well and tap water the pump has an easier job.

Sharing the 2514 name is encouraging, but it does not prove fit. On a system from another brand, compare the position of the brine seal, the ends of the permeate tube and the flow direction against the element you have now, or ask us before you order.

Storing and handling the element

Every element is shipped sealed in a bag with preservative solution. Leave it sealed until installation, keep it indoors away from direct sun, and do not allow it to freeze.

Once in use and wet, the element must never dry out. If the system will be out of use for a season, protect the elements against bacterial growth with Membrane Preservative.

Common questions