{"product_id":"4-x-40-freshwater-reverse-osmosis-membrane","title":"4\" x 40\" Freshwater Reverse Osmosis Membrane","description":"\u003cp\u003e\u003cstrong\u003eA large home or a business running on reverse osmosis cannot afford a slow tank refill or a creeping TDS reading.\u003c\/strong\u003e In Crystal Quest systems from 1,800 to 7,000 GPD, the 4\" x 40\" elements carry the whole load, so their condition decides how much purified water you get and how good it tastes.\u003c\/p\u003e\u003cp\u003eThe Crystal Quest 4\" x 40\" Freshwater Reverse Osmosis Membrane (CQE-RC-04086, the 4040 element size) is the replacement element listed for the 1,800, 4,000, 5,000 and 7,000 GPD Whole House Reverse Osmosis System and the same sizes of the Commercial and Medical Mid-Flow RO Systems. Because 4040 is a standard element size, it also fits other RO systems built for 4 x 40 inch membranes. It is a thin-film composite (TFC) element for pre-filtered, dechlorinated municipal or well water.\u003c\/p\u003e\u003ch3\u003eAt a glance\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCounts by system:\u003c\/strong\u003e one for 1,800 GPD, two for 4,000 GPD, three for 5,000 GPD and four for 7,000 GPD on the Whole House RO\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePublished with its test conditions:\u003c\/strong\u003e 99% nominal salt rejection (96% minimum) at 550 ppm, 150 psi, 77°F (25°C) and 15% recovery\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFreshwater class\u003c\/strong\u003e for feed water under 2,000 ppm TDS; brackish and seawater 4040 elements are sold separately\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eService life of 2 to 3 years;\u003c\/strong\u003e actual life depends on feed water quality, system configuration and usage\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWhat you are looking at\u003c\/h3\u003e\u003cp\u003eThe 4040 is the workhorse format of light commercial RO: a 4\" diameter, 40\" long spiral-wound element. Inside, many leaves of TFC membrane and mesh feed spacer are rolled around a perforated permeate tube. The larger diameter holds far more membrane than a 2.5\" element of the same length, which is why one 4040 can carry an entire 1,800 GPD system. A brine seal at the inlet end keeps feed water from bypassing the element. It ships in preservative solution with core tube protectors on each end.\u003c\/p\u003e\u003ch3\u003eHow it works and what keeps it working\u003c\/h3\u003e\u003ch4\u003eSeparation under pressure\u003c\/h4\u003e\u003cp\u003eThe system pump pushes feed water across the membrane harder than the osmotic pressure created by its dissolved salts. Water molecules pass into the permeate channels; dissolved ions stay in the feed and leave as concentrate. Crystal Quest rates these elements at 150 psi operating pressure. A Crystal Quest RO system sends about 1 gallon to drain for every 1 to 3 gallons of purified water, depending on your water chemistry and setup.\u003c\/p\u003e\u003ch4\u003eClean, then decide\u003c\/h4\u003e\u003cp\u003eOver time, mineral scale, organics and biological film build up on the membrane surface. Before replacing elements, check whether a cleaning will bring them back. Periodic cleaning can restore performance, but keep cleaning flows within the pressure-drop limits of 13 psi per element and 30 psi per pressure vessel. If rejection does not recover after cleaning, the membrane itself has aged and it is time for new elements.\u003c\/p\u003e\n\u003ch3\u003eWhat it reduces\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003ePrimary target:\u003c\/strong\u003e total dissolved solids: hardness minerals, sodium, chloride, sulfate and the other dissolved ions behind scale, spotting and off tastes. Crystal Quest whole house RO systems are rated for 96% minimum and 98.5% nominal salt rejection.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAlso held back:\u003c\/strong\u003e particles of every kind, microplastics included, are far too large to pass the membrane; the pre-filters catch most of them first.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eNot designed to handle:\u003c\/strong\u003e free chlorine (0.1 ppm maximum), sediment, and iron or manganese above 0.05 ppm. Feed hardness should be under 5 gpg on 1,800 GPD systems and under 15 gpg on 4,000 to 7,000 GPD systems. For salty groundwater or seawater, choose the \u003ca href=\"https:\/\/crystalquest.com\/products\/4-x-40-brackish-water-reverse-osmosis-membrane\"\u003e4\" x 40\" Brackish Water\u003c\/a\u003e or \u003ca href=\"https:\/\/crystalquest.com\/products\/4-x-40-seawater-desal-reverse-osmosis-membrane\"\u003e4\" x 40\" Seawater Desal\u003c\/a\u003e element instead.\u003c\/p\u003e\u003ch3\u003eWhy Crystal Quest\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe exact element and count\u003c\/strong\u003e for each Crystal Quest system size, from our own replacement tables.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExpert support for big systems:\u003c\/strong\u003e help reading your log, deciding clean or replace, and setting up the system again.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOver 1,000,000 people served since 1994.\u003c\/strong\u003e 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.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eWhere it fits\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"https:\/\/crystalquest.com\/products\/whole-house-reverse-osmosis-system\"\u003eWhole House Reverse Osmosis System\u003c\/a\u003e:\u003c\/strong\u003e 1,800 GPD (1), 4,000 GPD (2), 5,000 GPD (3), 7,000 GPD (4).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"https:\/\/crystalquest.com\/products\/reverse-osmosis-system-mid-flow\"\u003eCommercial Mid-Flow\u003c\/a\u003e and \u003ca href=\"https:\/\/crystalquest.com\/products\/medical-mid-flow-reverse-osmosis-system-500-7000-gpd\"\u003eMedical Mid-Flow\u003c\/a\u003e RO Systems,\u003c\/strong\u003e 1,800 to 7,000 GPD: use the quantity in your system's replacement table.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\u003ca href=\"https:\/\/crystalquest.com\/products\/reverse-osmosis-system-high-flow\"\u003eHigh-Flow RO Systems\u003c\/a\u003e\u003c\/strong\u003e are also built on 4040 elements; call us to confirm the part for your unit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSmaller systems:\u003c\/strong\u003e 750, 1,500 and 2,500 GPD use the \u003ca href=\"https:\/\/crystalquest.com\/products\/2-5-x-40-ro-membrane\"\u003e2.5\" x 40\" element\u003c\/a\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eRO membranes are not returnable under our \u003ca href=\"https:\/\/crystalquest.com\/policies\/refund-policy\"\u003erefund policy\u003c\/a\u003e, so check the part number on your current elements or call us before ordering.\u003c\/p\u003e\u003ch3\u003eStandard 4040 format\u003c\/h3\u003e\u003cp\u003eThis is a low-energy freshwater element in the standard 4040 (4\" x 40\") format used in 4\" x 40\" membrane housings and pressure vessels, 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 \u003ca href=\"https:\/\/crystalquest.com\/pages\/contact-us\"\u003econtact us\u003c\/a\u003e before ordering.\u003c\/p\u003e\u003ch3\u003eStorage and handling\u003c\/h3\u003e\u003cp\u003eEach 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, \u003ca href=\"https:\/\/crystalquest.com\/products\/membrane-persavtive\"\u003eMembrane Preservative\u003c\/a\u003e is used to protect the elements against damage from bacterial growth.\u003c\/p\u003e\u003ch3\u003eCommon questions\u003c\/h3\u003e\u003cdiv class=\"cq-product-faq\"\u003e\n\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eWhich systems use the 4\" x 40\" element?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eThe 1,800, 4,000, 5,000 and 7,000 GPD Whole House Reverse Osmosis System, and the same sizes of the Commercial and Medical Mid-Flow RO Systems.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eHow many elements do I need?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eUse the count in your system's replacement table. On the Whole House Reverse Osmosis System it is one for 1,800 GPD, two for 4,000 GPD, three for 5,000 GPD and four for 7,000 GPD.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eIs this a standard 4040 RO membrane?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eIt is a 4\" x 40\" element, the 4040 format. Fit is about more than the format name, so order by the part number your Crystal Quest system lists, or call us to confirm.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eShould I clean or replace my 4040 membranes?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eIf performance dropped because of scale or fouling, a cleaning can bring it back. If rejection stays low after cleaning and fresh pre-filters, replace the elements.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eHow long do they last?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003ePlan on 2 to 3 years. Actual life depends on feed water quality, system configuration and usage.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eDo I need to flush a new element?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eYes. New elements ship in a preservative solution. Flush for at least 1 hour and discard all permeate and concentrate made during the flush.\u003c\/p\u003e\u003c\/details\u003e\u003cdetails\u003e\u003csummary\u003e\u003cstrong\u003eFreshwater, brackish or seawater?\u003c\/strong\u003e\u003c\/summary\u003e\u003cp\u003eThis is the freshwater element. Crystal Quest also sells 4\" x 40\" brackish water and seawater desal elements. Choose the class your system and feed water are designed for, and ask Crystal Quest if you are unsure.\u003c\/p\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n###\n\u003ch3\u003eElement specifications\u003c\/h3\u003e\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003e\u003cstrong\u003eValue\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eMembrane type\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003eThin-film composite (TFC) reverse osmosis element\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eApplication\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003eFreshwater\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eElement size\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003e4\" x 40\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003ePart number\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003eCQE-RC-04086\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eListed replacement for\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003eWhole House Reverse Osmosis System 1,800 GPD (1), 4,000 GPD (2), 5,000 GPD (3), 7,000 GPD (4); Commercial and Medical Mid-Flow RO Systems 1,800 to 7,000 GPD (quantity per system table)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eFeed water\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003ePre-filtered and dechlorinated; free chlorine 0.1 ppm maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eStart-up\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003eFlush at least 1 hour; discard all permeate and concentrate from the flush\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd valign=\"middle\"\u003eService life\u003c\/td\u003e\n\u003ctd valign=\"middle\"\u003e2 to 3 years*\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eElement performance\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eRated production\u003c\/td\u003e\n\u003ctd\u003e2,500 GPD at 150 psi, 550 ppm feed, 77°F (25°C), 15% recovery; actual output drops with colder or saltier water\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNominal salt rejection\u003c\/td\u003e\n\u003ctd\u003e99% (96% minimum)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTest conditions\u003c\/td\u003e\n\u003ctd\u003e550 ppm feed, 150 psi, 77°F (25°C), 15% recovery\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating pressure\u003c\/td\u003e\n\u003ctd\u003eRated maximum: 600 psi; suggested operating range: 100 to 150 psi\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum temperature\u003c\/td\u003e\n\u003ctd\u003e113°F (45°C)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003epH range\u003c\/td\u003e\n\u003ctd\u003eRated 2 to 11; suggested 5 to 11 for continuous operation; cleaning 2 to 12\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFree chlorine tolerance\u003c\/td\u003e\n\u003ctd\u003e0.1 ppm maximum. Remove chlorine and chloramine before the membrane with carbon pre-filtration (Crystal Quest whole house RO systems include this).\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum turbidity\u003c\/td\u003e\n\u003ctd\u003e1 NTU\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSilt density index\u003c\/td\u003e\n\u003ctd\u003eLess than 5 SDI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum pressure drop\u003c\/td\u003e\n\u003ctd\u003e13 psi per element; 30 psi per pressure vessel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e\u003cstrong\u003eFeed water limits for the system\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eTotal dissolved solids\u003c\/td\u003e\n\u003ctd\u003eUnder 2,000 ppm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHardness\u003c\/td\u003e\n\u003ctd\u003eUnder 5 gpg (1,800 GPD); under 15 gpg (4,000 to 7,000 GPD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIron and manganese\u003c\/td\u003e\n\u003ctd\u003eUnder 0.05 ppm each\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSilica and organics\u003c\/td\u003e\n\u003ctd\u003eUnder 1 ppm each\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFree chlorine\u003c\/td\u003e\n\u003ctd\u003eNone (remove upstream)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFeed temperature\u003c\/td\u003e\n\u003ctd\u003e40°F to 105°F\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003cp\u003e*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.\u003c\/p\u003e\u003cp\u003e\u003cimg width=\"1024\" height=\"571\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/1286\/9985\/files\/RO_Membrane_Illustration_1024x1024.png?v=1615830985\" alt=\"Illustration of a Crystal Quest freshwater reverse osmosis membrane element\"\u003e\u003c\/p\u003e\n","brand":"Crystal Quest Water Filters","offers":[{"title":"Single","offer_id":67868654338281,"sku":"CQE-RC-04086","price":286.35,"currency_code":"USD","in_stock":true},{"title":"Pack of 2","offer_id":67868654371049,"sku":"CQE-RC-04086-2PK","price":572.7,"currency_code":"USD","in_stock":true},{"title":"Pack of 4","offer_id":67868654403817,"sku":"CQE-RC-04086-4PK","price":1145.4,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0814\/4512\/6377\/files\/4-x-40-freshwater-reverse-osmosis-membrane-crystal-quest-water-filter-cartridges-1263586066.webp?v=1793834531","url":"https:\/\/clearwaterworld.com\/products\/4-x-40-freshwater-reverse-osmosis-membrane","provider":"Clearwater World","version":"1.0","type":"link"}