Unicel C-6350 | 50 sq ft Spa Filter Cartridge

By Unicel
SKU: C-6350
$54.99

Let's Ensure This Fits Your Model

Check out the Filter Guide to see if this filter fits your hot tub model.

If you have questions, call us at (208) 973-1384 or send us an email to hello@leisuretimeinc.com

If possible, please have your hot tub’s serial number ready when you contact our team.

Description

The Unicel C-6350 delivers 50 square feet of filtration built on Unicel's 3 oz Reemay® polyester media. Built to meet or exceed OEM specifications, it's the kind of replacement that performs like the original — and often outlasts it.

Filtration is the quiet backbone of clean spa water. Every soak leaves behind body oils, lotions, hair, and fine debris, and the cartridge is what removes all of it before it clouds the water, feeds bacteria, or coats your plumbing. When a filter is worn or clogged, the effects spread everywhere: dull water, higher chemical use, softer jets, and a pump and heater straining against restricted flow.

What separates a Unicel from a bargain cartridge is what it's built from. The Reemay media uses trilobal fibers — three-lobed rather than round — which pack substantially more surface area into the same material, balancing dirt-holding capacity, cleanability, and chemical resistance. Add chemical-resistant end caps with an exact OEM fit, uniform pleat folds that keep flow strong and pressure loss low, and a solid core that holds its shape under pressure, and you get a cartridge that performs through cleaning after cleaning. Made in the USA, backed by more than 45 years of filter-cartridge expertise.

Pro Tip: Match the part number before you order, not just the square footage. Plenty of cartridges share a 50 sq ft rating but differ in diameter, length, and end-cap style — and a filter that's the right area but the wrong shape won't seal properly, letting unfiltered water bypass the media entirely. Pull your current cartridge, read the number printed on it, and match that.

Brand

UNICEL®

Key Features
  • 50 sq ft of filtration — full OEM-spec filtration area
  • Reemay polyester media — balances dirt-holding capacity, cleanability, and chemical resistance
  • Chemical-resistant end caps — durable plastic with an exact OEM fit
  • Uniform pleat folds — enhance flow, minimize pressure loss, and use the full pleat surface
  • Solid core — maintains structural integrity and optimized flow under pressure
  • Made in the USA — built to exceed OEM standards
How It Works

Water is drawn through the cartridge's pleated media as your spa circulates. Pleating creates the capacity: folding the fabric back and forth packs 50 square feet of filtering surface into a cartridge sized to drop into your filter compartment. More surface means water passes through more slowly and thoroughly, capturing finer particles, and it means the filter holds far more debris before flow starts to drop off.

Two design details do the heavy lifting. First, the Reemay media: its trilobal fibers present considerably more surface area than standard rounded fibers, giving more places for dirt to be captured and a smooth surface that releases it readily when rinsed. Unicel's 3 oz media captures debris down to an average of 20 microns — far finer than the eye can see. Second, the pleat geometry: evenly spaced folds let water reach the full depth of every pleat, so the entire surface does filtering work instead of some folds being pinched shut. That's what keeps flow strong and pressure loss low while holding more debris between cleanings.

Pro Tip: A clean filter protects your equipment, not just your water. As the pleats load up with body oils, your pump has to work harder against the restriction, and reduced flow across the heater can trigger flow-related errors. Regular rinsing and periodic deep cleaning is the cheapest protection there is for the expensive parts of your spa.

Directions for Use

Installation

  1. Turn off power to the spa at the breaker before servicing the filter compartment.
  2. Open the filter lid and clear any debris from the compartment.
  3. Remove the old cartridge, noting its orientation.
  4. Seat the new cartridge squarely in the filter well, fully seated top and bottom so it seals properly.
  5. If your spa uses more than one cartridge, replace them at the same time so they wear evenly.
  6. Close the lid, restore power, and run the circulation to confirm normal flow.

Routine Cleaning

  1. Every two to four weeks: remove the cartridge and rinse gently with a garden hose, working between the pleats from top to bottom. A soft brush cleaning tool helps.
  2. Periodically: soak or treat the cartridge with a dedicated filter cleaner to dissolve the body oils and buildup a rinse can't remove, then rinse it off.
  3. Let it dry fully before returning it to service whenever possible.

When to Replace

  • The cycle between cleanings gets noticeably shorter
  • Low water flow or high differential pressure
  • The media has a tear
  • The center core collapses

Cartridge life depends on routine maintenance and your spa's water chemistry.

Pro Tip: Skip the pressure washer — a garden hose is the right tool. It's tempting to blast a dirty cartridge clean, but high-pressure water drives debris deeper into the media and can tear the pleats or damage the fibers, permanently reducing how well the filter works. Steady hose pressure worked patiently down each pleat gets it cleaner and keeps the cartridge intact far longer.

Specifications
  • Brand: Unicel (Meissner Mfg. Co., Inc.)
  • Part Number: C-6350
  • Product Type: Replacement spa filter cartridge
  • Filtration Area: 50 sq ft
  • Media: Reemay spunbonded polyester, 3 oz basis weight
  • Filtration Rating: Captures debris to an average of 20 microns
  • End Caps: Durable plastic, chemical-resistant, exact OEM fit
  • Core: Solid core for structural integrity and optimized flow
  • Pleats: Uniform folds for enhanced flow and efficiency
  • Standards: Built to meet or exceed OEM specifications
  • Cleaning: Rinse gently with a garden hose every two to four weeks; deep clean periodically with filter cleaner. Do not pressure wash.
  • Replace When: Cleaning cycles shorten, flow drops, the media tears, or the center core collapses
  • Origin: Made in the USA
  • Shipping: Standard ground; not classified as a hazardous material

  • Outer Diameter: 6"
  • Length: 14"
  • Top End Cap: 1-15/16"open
  • Bottom End Cap: 1-15/16"open
  • Pleat Count: 142
  • Media: 3 oz.
  • Filtration Square Footage: 50 sq. ft
Compatibility

Unicel cartridges are interchangeable with all major filter brands, each one built to the original manufacturer's specifications for a proper fit and seal. The C-6350 is the 50 square foot cartridge in Unicel's lineup.

To confirm this is the right filter for your spa, the most reliable method is to pull your current cartridge and read the part number printed on it. If that number has worn off, measure the old cartridge — its diameter, length, and the size and style of the openings at each end — and match those dimensions. Our filter guide can help you check your hot tub model, and our team is happy to confirm fitment before you order. Also check how many cartridges your spa takes, since many models use more than one. For upkeep, pair it with a dedicated filter cleaner for periodic deep cleaning.

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  • Limelight Flair 2018-Current
  • Limelight Flash 2018-Current
  • Limelight Pulse 2018-Current

This is a replacement for the Hot Spring Limelight 78161 Filter Cartridge

Most products purchased from our online shop within the last 30 days are eligible for return. Please review our return policy to see the list of items that cannot be returned.

Some major items that are non-returnable:

  • Gift cards
  • Electronics
  • Pumps / Motors
  • Hot Tubs
  • Closeouts
  • Fireplaces
  • Electric Fireplaces
  • Massage Chairs
  • See return policy below for full list of non-returnables.

UNICEL® Brand FAQs

Who makes Unicel filters?

Unicel filters are made byMeissner Mfg. Co., Inc., a family business that began as a small contract sewing operation in thelate 1950sand moved into pool filtration through the 1970s. By the end of that decade the company was producing cartridge filters for the industry'soriginal equipment manufacturers, and in1985it introduced the Unicel brand as aftermarket replacements. It's still owned and operated by the Meissner family today.

Are Unicel filters as good as the original manufacturer's filter?

Unicel builds its cartridges tomeet or exceed original equipment specifications— and that's a meaningful distinction here, because the company produced cartridges for the industry's OEMs before it ever launched its own brand. Unicel cartridges usedurable, chemical-resistant end capswith an exact fit,high-capacity media,uniform pleatsfor optimal flow, and asolid corethat resists collapsing under pressure.

Where are Unicel filters made?

Unicel filters are manufactured inCalifornia, with components sourcedexclusively in the United States. The line comprisesnearly 500 products, covering replacement cartridges, D.E. grids, filter discs, and related parts.

How do I find the right Unicel filter for my spa?

Unicel cartridges areinterchangeable with all major filter brands, and each one cross-references to a list of original equipment part numbers. The most reliable method is topull your current cartridge and read the part number printed on it, then match it to the Unicel cross-reference. If the number has worn off,measure your old cartridge— diameter, length, and the size and style of the openings at each end — and match those instead. Also confirmhow many cartridgesyour spa uses.

How long does a Unicel filter last?

Cartridge life depends on how heavily the spa is used, yourwater chemistry, and how consistently you clean the filter. Many Unicel cartridges useReemay® polyester media, whosetrilobal fibersprovide considerably more surface area than standard rounded fibers — which increases dirt-holding capacity and extends the time between cleanings. With regular rinsing and periodic deep cleaning, a well-maintained cartridge commonly serves a year or more.

When should I replace my filter instead of cleaning it?

Replace the cartridge when thecycle between cleanings becomes noticeably shorter, when you seelow water flowor high differential pressure, when the media has atear, or if thecenter core collapses. Pleats that stay permanently flattened or discolored after a proper cleaning are another sign the cartridge has reached the end of its service life.

About UNICEL®

Unicel is the nation's leading manufacturer of replacement filter cartridges for pools and spas — and the story behind it is a genuinely American one. In the late 1950s, Richard T. Meissner started a small part-time contract sewing operation. Through the 1970s, Meissner Mfg. Co., Inc. moved into swimming pool filter bags, then D.E. grid element covering, and by the end of that decade the company was producing cartridge filters for the industry's original equipment manufacturers.

That's the detail that matters most: Unicel was building the filters that went into new spas long before it sold a replacement. In 1985, the company introduced the UNICEL brand so dealers and technicians could source elements built to O.E.M. specifications from a single place — even for equipment brands they didn't carry. Today the line spans nearly 500 products, all manufactured in California with components sourced exclusively in the USA.

By staying focused on one thing — filtration — Unicel has built deep expertise in a critical corner of the industry, from media development to cartridge design. Every cartridge is built with chemical-resistant end caps for an exact fit, high-capacity filter mediauniform pleats for optimal flow, and a solid core that holds its shape under pressure. Meissner Mfg. Co., Inc. remains owned and operated by the Meissner family, still recognized for quality and service. American-made products, world-class service.