50 GPD Reverse Osmosis Replacement Membrane

Your countertop RO or bottleless water cooler takes longer and longer to make a glass, and the water has started to taste like the tap again. Both point to the same part: the reverse osmosis membrane at the heart of the system.

This 50 GPD thin film composite (TFC) membrane is the reverse osmosis stage listed for the Crystal Quest Countertop Reverse Osmosis System and the SHARP, TURBO and Hybrid UF + RO bottleless water coolers. It measures 1.75" x 11.75" for 2" x 12" residential membrane housings and reduces dissolved contaminants, including lead, mercury, cadmium, trivalent chromium, fluoride, nitrates, sodium and radium.

At a glance

The exact membrane your countertop RO or bottleless cooler lists, part CQE-RC-04041
Restores purified water with lower TDS and a clean taste
Reduces dissolved solids such as lead, fluoride, nitrates and sodium
Up to 99% reduction of dissolved solids (TDS)
2 to 3 years of service, depending on feed water quality, system configuration and usage

What you are looking at

A compact spiral wound element: TFC membrane sheets and polyethylene netting rolled around a perforated center tube, held in polyolefin wraps, with polypropylene end caps and Buna-N gaskets. The end with the two small O-rings goes into the housing first.

How a 50 GPD RO membrane works

A thin polyamide film does the separating

The thin film in "thin film composite" is a polyamide layer laid over a porous support and a polyester backing. Water molecules pass through the polyamide; dissolved salts and metals, which travel through water as charged ions, are held back at the surface.

Pressure pushes the water through

Water naturally moves toward the saltier side of a membrane. Reverse osmosis applies pressure to drive it the other way, so purified water collects in the center tube while the rejected solids are rinsed to drain. Crystal Quest RO systems send 1 gallon to drain for every 1 to 3 gallons of purified water.

Why pressure matters so much on a countertop system

A countertop RO or bottleless cooler depends on the water pressure it is fed. The membrane is rated 50 GPD at 50 psi; inside the Countertop Reverse Osmosis System, about 60 psi gives the best output. Below that, the membrane still works, but production slows. Pressure also affects how well the membrane rejects dissolved solids, so low pressure can show up on a TDS meter as well as in a slow fill.

Cold water and hard water

Very cold water moves through the membrane more slowly and can slow production to a trickle until it warms up. Hard water is the other common problem: hardness can form a crystallized layer of scale on the membrane, which cuts output. If your water is very hard, ask Crystal Quest about softening ahead of the RO.

Keep chlorine off the membrane

Chlorine attacks the polyamide film and the damage is permanent. The carbon stage ahead of the membrane removes it, so replace the pre-filter on schedule and the membrane will last longer.

GPD itself is the membrane's daily production at its standard test conditions; your real output depends on pressure, temperature and TDS.

What it reduces

Primary target: total dissolved solids, including lead, mercury, cadmium, trivalent chromium, fluoride, nitrates, sodium and radium.

Handled by the system's other stages: chlorine, taste and odor (carbon and polishing stages). The membrane is one stage of your countertop RO or cooler, not a stand-alone filter.

Why Crystal Quest

The listed part, not a "fits most" membrane: the 50 GPD rating your Crystal Quest countertop RO or cooler was designed around.
Practical guidance on pressure, cold water and hardness, so you know what normal output looks like.
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

Countertop Reverse Osmosis System
SHARP, TURBO and Hybrid UF + RO bottleless water coolers
Housing: 2" x 12" residential membrane housing; membrane size 1.75" x 11.75".

Thunder under-sink RO systems use the 100 GPD membrane as standard. Membranes are not returnable, so check the label on your current membrane before ordering.

Common questions

Which systems use the 50 GPD membrane?

The Crystal Quest Countertop Reverse Osmosis System and the SHARP, TURBO and Hybrid UF + RO bottleless water coolers list it as their replacement membrane. You can also check the label on the membrane you are replacing.

Can I use it in a Thunder under-sink RO?

Thunder systems are built around the 100 GPD membrane as standard, with 75 GPD listed as an option. Use the rating your system lists, and ask Crystal Quest before changing it.

Why is my system making less water?

Cold water, low water pressure and higher TDS all reduce membrane production. The membrane is rated at 50 psi; the countertop system performs best at about 60 psi. If output stays low with fresh cartridges and normal pressure, the membrane may be due.

How long does a 50 GPD RO membrane last?

About 2 to 3 years. Actual life depends on feed water quality, system configuration and usage.

Does hard water affect the membrane?

Yes. Hardness can form a crystallized layer of scale on the membrane surface and reduce output. On very hard water, ask Crystal Quest about softening ahead of the RO.

How do I replace the membrane?

Turn off the water, unscrew the membrane housing cap, pull out the old membrane and push the new one in, end with the two small O-rings first, until it is fully seated. Then reconnect, check for leaks and flush as your system manual directs.

Specifications for your selection

Single

SKU: CQE-RC-04041
Diameter (width): 1.75 in
Length (height): 11.75 in
Replace every: 2 to 3 years

Membrane type: Thin-film composite (TFC) reverse osmosis membrane
Production rating: 50 GPD (gallons per day)
Part number: CQE-RC-04041
Membrane size: 1.75" x 11.75"
Housing format: 2" x 12" residential membrane housing
Listed replacement for: Countertop Reverse Osmosis System; SHARP, TURBO and Hybrid UF + RO bottleless water coolers
Construction: Polypropylene end caps, polyolefin inner and outer wraps, polyethylene netting, Buna-N gasket end caps
Operating pressure: 20 to 60 psi (1.4 to 4.1 bar)
Operating temperature: 40°F to 90°F (4°C to 32°C)
Replacement interval: 2 to 3 years; actual life depends on feed water quality, system configuration and usage

Performance curves

Rated 50 GPD at 77°F (25°C), 50 psi, 250 ppm feed.

Figure 1. Permeate flow vs feed temperature at 40, 50 and 60 psi, normalized to the rated flow at 77°F (25°C) and 50 psi.

Data for Figure 1

Expected permeate flow in GPD by feed temperature and feed pressure
Feed temperature	40 psi	50 psi	60 psi
40°F (4°C)	19	24	29
50°F (10°C)	23	29	35
60°F (16°C)	28	36	44
70°F (21°C)	34	44	53
77°F (25°C)	39	50	61
85°F (29°C)	45	57	69
90°F (32°C)	48	62	75

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 3 psi for the 250 ppm test feed). Shaded: rated operating range, 20 to 60 psi; darker: recommended, 50 to 60 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)
10 psi	4	5	7
20 psi	10	13	18
30 psi	17	21	29
40 psi	23	28	39
50 psi	29	36	50
60 psi	35	44	61

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, storage tank back pressure and element condition.

Membrane specifications

Specification	Value
Membrane type	Thin-film composite (TFC) reverse osmosis membrane
Production rating	50 GPD (gallons per day)
Part number	CQE-RC-04041
Membrane size	1.75" x 11.75"
Housing format	2" x 12" residential membrane housing
Listed replacement for	Countertop Reverse Osmosis System; SHARP, TURBO and Hybrid UF + RO bottleless water coolers
Construction	Polypropylene end caps, polyolefin inner and outer wraps, polyethylene netting, Buna-N gasket end caps
Operating pressure	20 to 60 psi (1.4 to 4.1 bar)
Operating temperature	40°F to 90°F (4°C to 32°C)
Salt rejection	Up to 99%
Chlorine	Remove ahead of the membrane with carbon pre-filtration
Drain water (Crystal Quest RO systems)	1 gallon to drain for every 1 to 3 gallons of purified water
Service life	2 to 3 years*

*Service life is an estimate. Actual life depends on feed water quality, system configuration and usage.

Plan on a new membrane every 2 to 3 years. Actual life depends on feed water quality, system configuration and usage.
Compare tap-water and RO-water TDS. A steady rise in RO-water TDS, or lower production that fresh pre-filters and normal pressure do not restore, means the membrane is due.
Replace pre-filters on schedule; on chlorinated city water, once a year is best practice.
Follow the membrane replacement steps in your system manual. In brief: turn off the water and relieve pressure, unscrew the membrane housing cap, pull out the used membrane, push the new one in with its O-ring end first until it is fully seated, reconnect the tubing with thread seal tape, then check for leaks and flush before use.

Keep your cooler or countertop RO pouring clean. Choose Subscribe & save above to have your next membrane arrive on the schedule you set.

Listed as the replacement membrane (CQE-RC-04041) for the Crystal Quest Countertop Reverse Osmosis System and the SHARP, TURBO and Hybrid Ultrafiltration + Reverse Osmosis Bottleless Water Coolers.

It is the 1.75" x 11.75" residential format for 2" x 12" membrane housings. Crystal Quest Thunder under-sink RO systems use the 100 GPD membrane as standard, so order that rating for a Thunder.