Unicel C-5315 | 15 sq ft Intex Type B Pool Filter

• Built to be rinsed and reused: 3 oz Reemay polyester media engineered to hold up through repeated cleanings rather than being discarded after a couple of weeks.
• Chemical-resistant plastic end caps: Molded to an exact OEM fit and built to resist degradation from chlorine and sun exposure across a full season.
• 15 square feet of filtration area: Matches the Intex Type B specification exactly, restoring full rated performance with no reduction in surface area.
• 70 widely spaced pleats: Open folds that release grass, dirt, and leaf debris under a garden hose instead of trapping it permanently.
• Solid molded core: Holds pleat geometry under flow and resists the collapse that lets water channel past the media.
• 1-7/8" open ends, top and bottom: Standard Type B configuration that drops straight into the pump housing with nothing to thread or align.
• Fits thirteen Intex pump models: One cartridge covers the Krystal Clear range that uses Type B.
• 100% polyester Reemay media: Smooth-surfaced fabric that resists chemical degradation and stands up under pressure.
• Made in the USA: Manufactured by Meissner Manufacturing to meet or exceed OEM specification.

The cartridge sits inside the pump housing with both ends open. When the pump runs, it draws water from inside the hollow core, dropping the pressure there below that of the surrounding water. That difference pushes water inward through the pleated media from every direction at once, across the full circumference and the entire 10" height. Filtered water exits through the open ends and returns to the pool.

Particles are captured in the depth of the polyester fibers rather than sitting on the outer surface. On an above-ground pool that means grass, dirt tracked in on feet, leaves, pollen, insects, sunscreen, and body oils all embed in the fabric as water passes through. Depth loading is why a cartridge that still looks reasonably clean from the outside can already be meaningfully restricted — most of what it has collected is inside the fibers, not visible on them.

Fifteen square feet is a modest amount of filtration area, and that is worth saying plainly rather than glossing over. Intex pumps are sized to circulate a pool volume over several hours of daily running, not to filter continuously the way a spa does. The cartridge is matched to that duty. What it means practically is that this filter loads faster than a large spa cartridge would, and the maintenance rhythm is correspondingly shorter. That is not a shortcoming of the cartridge — it is the nature of a compact pump on a pool that sits open to the yard all summer.

Declining flow from the return jet is the most reliable early signal that a rinse is due. On an Intex pump you will usually notice the return stream weakening before the water itself looks any different.

Pro Tip: Rinse it before the debris dries. This matters far more on an above-ground pool than on a spa. Grass clippings, pollen, and fine dirt come out of the pleats almost effortlessly while they are still wet and loose. Leave the cartridge sitting in a hot pump housing, or set it out in the sun to dry with a full load in it, and that same debris bakes onto the fibers into a crust that a hose will not shift. If you are pulling the cartridge for any reason, give it a rinse while it is out, even if you were not planning to clean it. Ten seconds then saves a soak later.

Installation

1. Switch the pump off and unplug it before opening the housing. Never open a running pump.
2. Close the plunger valves at the pool wall if your setup has them, or the housing will drain the pool line when you open it.
3. Open the pump housing lid and lift the old cartridge straight out. Let it drain as you go.
4. Rinse out any debris and grit that has settled in the bottom of the housing.
5. Drop the new cartridge in with either end up — both ends are open and identical, so there is no wrong orientation.
6. Confirm it sits down squarely in the housing without rocking or leaning.
7. Refit the lid, open the plunger valves, and plug the pump back in.
8. Run it for a minute and check that the return jet flow is strong. A clear improvement over the old cartridge is expected.

Routine Cleaning

• Every few days in peak season: Pull the cartridge and rinse with a garden hose. Spray downward into the pleats at an angle, rotating steadily so every fold gets direct attention. The wide pleat spacing means a hose genuinely reaches the base of each one.
• After heavy use or a storm: Rinse the same day. A pool party or a windy afternoon puts more into the filter than a normal week does.
• Every few weeks: Soak in a dedicated filter cleaning solution to lift the sunscreen, body oils, and fine grime that plain rinsing leaves behind. Rinse thoroughly afterward — cleaner left in the pleats causes foaming when the pump restarts.
• Rotate two cartridges if you can: A spare lets you put a clean one in immediately while the other dries completely. A fully dried cartridge sheds trapped debris far more easily at the next rinse.
• At end of season: Deep-clean, dry completely, and store somewhere dry and out of sunlight. A cartridge put away damp will not be worth using next spring.

Important Cautions

• Do not use a pressure washer. High-pressure spray tears media fibers and destroys pleat geometry, often without any visible damage, and torn media passes unfiltered water straight through.
• Do not run the pump without a cartridge installed. Debris drawn straight into the pump can damage it, and an Intex pump costs many times what a cartridge does.
• Do not clean with dish soap, laundry detergent, or household cleaners. These leave residues that foam persistently and are difficult to rinse out.
• Do not leave a loaded cartridge to dry in direct sun. Debris bakes onto the fibers and becomes very hard to remove.
• Do not force a cartridge that does not seat easily. Resistance means a fitment mismatch — most likely a Type A and Type B mix-up.
• Do not boil, bleach, or machine-wash the cartridge.

When to Replace

Replace the cartridge when you see torn or separated media, cracked or deformed end caps, a soft or collapsing core, pleats that have permanently lost their shape or matted together, staining that no longer responds to a soak, or a persistent drop in return flow that thorough cleaning no longer restores. Because this cartridge is designed for repeated cleaning rather than disposal, service life depends far more on how it is maintained than on the calendar — rinsed regularly and stored dry over winter, it will typically outlast a full season comfortably. Left to dry out loaded, or cleaned with a pressure washer, it will not.

• Brand: Unicel
• Manufacturer: Meissner Manufacturing Co., Inc.
• Part Number: C-5315
• Product Type: Replacement pool filter cartridge, Intex Type B
• Filtration Area: 15 sq. ft.
• Pleat Count: 70
• Filter Media: 3 oz. Reemay polyester, 100% polyester
• Outer Diameter: 5-3/4"
• Length: 10"
• Top End Cap: Open, 1-7/8" inner diameter
• Bottom End Cap: Open, 1-7/8" inner diameter
• Core: Solid molded, full-length
• End Cap Material: Chemical-resistant molded plastic, exact OEM fit
• Replaces OEM: Intex 29005E, Intex 59905E (Type B)
• Cross-References: Pleatco PIN20, Filbur FC-3752, Darlly 50152
• Fits Pump Models: 56611, 56612, 56621, 56622, 56633, 56634, 59901E, 59905E, FP621R, 520R, 520, 633, 51
• Quantity Per Pump: One
• Reusable: Yes — designed for repeated rinsing and cleaning rather than disposal
• Cleaning Method: Hose rinse every few days in season; cleaning solution soak every few weeks. Do not pressure wash.
• Storage: Deep-clean and dry completely before off-season storage; keep out of direct sunlight
• Not Compatible With: Intex Type A pumps, and any housing outside the dimensions listed above
• Origin: Made in the USA
• Shipping: Standard ground; not classified as a hazardous material

Replaces These OEM Part Numbers

• Intex 29005E — Type B
• Intex 59905E — Type B

Cross-Reference Part Numbers

• Pleatco PIN20
• Filbur FC-3752
• Darlly 50152

Fits These Intex Filter Pump Models

• 56611, 56612
• 56621, 56622
• 56633, 56634
• 59901E, 59905E
• FP621R, 520R, 520, 633, and 51

How to Confirm Fitment

Intex identifies its pool cartridges by letter, and the letters are not interchangeable. Type B is the larger of the two common sizes, and this is Type B. A Type A cartridge will not work in a Type B pump. Before ordering, check the letter marked on your pump or old cartridge, then confirm against these measurements:

• Outer diameter: 5-3/4"
• Overall length: 10"
• Top opening: 1-7/8", open
• Bottom opening: 1-7/8", open

Pro Tip: Getting Type A and Type B mixed up is comfortably the most common ordering mistake on Intex filters, and it is easy to see why — the boxes look almost identical and the letter is often the smallest thing printed on them. Check the letter first, then verify with a tape measure. The letter is usually marked on the pump housing itself as well as on the cartridge, so if your old filter has weathered past reading, look at the pump. And if you own more than one Intex product, do not assume they match: it is entirely normal for a household to have one pump taking Type A and another taking Type B.