Buying the wrong replacement cartridge for an inflatable spa is the most common mistake in this category, and it is almost always a fitment problem rather than a quality problem. Hot tub filters for inflatable tubs are not universal. They split into two families that look nearly identical from across the patio: Type VI screw-in cartridges for Coleman SaluSpa and Lay-Z-Spa, and Type S1 drop-in cartridges for Intex PureSpa. A cartridge from the wrong family will not seat in the housing, and a cartridge that is close but not exact traps less debris than you paid for. We compared ten of the highest-rated cartridges on the market across fitment, media construction, and real owner feedback so you can match your tub before you order.
Fitment matters because the cartridge is the only barrier between the debris in your water and the pump and heater underneath. Owners on r/hottub describe the small cartridge that comes with a budget inflatable spa as effectively a daily change, which is the single most common complaint in this category. Once you start matching part numbers instead of guessing, that problem becomes much easier to solve. If you are still choosing the tub itself, our best inflatable hot tubs guide and hot tub picks tested cover the spa side of the decision.
This roundup covers the cartridges themselves, plus a measurement protocol, a brand-to-part-number map, and a cleaning and rotation routine that extends cartridge life. Every rating and review count below is copied straight from the product data, and every dimension comes from the manufacturer listing rather than an estimate.
Table of Contents
- Top 3 Picks: Best Hot Tub Filters for Inflatable Tubs (October 2026)
- Best Hot Tub Filters for Inflatable Tubs at a Glance
- 1. Best Hot Tub Filters for Inflatable Tubs: Bestway SaluSpa Type VI 60311E 2-Pack
- 2. Best Hot Tub Filters for Inflatable Tubs: Volca Spares Type VI Multi-Pack
- 3. Best Hot Tub Filters for Inflatable Tubs: Intex Type S1 29011E 6-Pack
- 4. Best Hot Tub Filters for Inflatable Tubs: POOLPURE Type S1 29001E 4-Pack
- 5. Best Hot Tub Filters for Inflatable Tubs: KGC Type VI 90352E 4-Pack
- 6. Best Hot Tub Filters for Inflatable Tubs: Slamate Type S1 12-Pack
- 7. Best Hot Tub Filters for Inflatable Tubs: SORSWEET Type VI 12-Pack
- 8. Best Hot Tub Filters for Inflatable Tubs: POOLPURE Type VI 90352E Cartridge
- 9. Best Hot Tub Filters for Inflatable Tubs: Intex Type S1 29001E 12-Pack
- 10. Best Hot Tub Filters for Inflatable Tubs: LYJHKJ Type VI 4-Pack
- How to Choose Hot Tub Filters for Inflatable Tubs
- Hot Tub Filters for Inflatable Tub Brands: Quick Compatibility Map
- How to Clean and Rotate Hot Tub Filters for Inflatable Tubs
- Frequently Asked Questions
- Our Final Pick for Hot Tub Filters for Inflatable Tubs
Top 3 Picks: Best Hot Tub Filters for Inflatable Tubs (October 2026)
Three cartridges stood out once we lined up fitment, media weight, and owner feedback. The Bestway OEM cartridge wins on exact fit and longevity, the Intex six-pack leads on rating, and the POOLPURE Type VI is the strongest aftermarket option for SaluSpa and Lay-Z-Spa owners.
Bestway SaluSpa Type VI 2-Pack
- Genuine Bestway part 60311E
- Type VI screw-in fit
- Two cartridges per pack
Intex Type S1 PureSpa 6-Pack
- Genuine Intex cartridge
- Works across PureSpa models
- Reusable when rinsed weekly
POOLPURE Type VI Cartridge
- Covers SaluSpa and Lay-Z-Spa
- Trilobal fabric 25% thicker
- Reinforced centre support
Best Hot Tub Filters for Inflatable Tubs at a Glance
All ten cartridges compared side by side. Read the fits column first, because the Type VI and Type S1 families are not interchangeable.
| Product | Specifications | Action |
|---|---|---|
| Bestway SaluSpa Type VI 2-Pack |
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Check Latest Price |
 Volca Spares Type VI Filter |
|
Check Latest Price |
| Intex Type S1 PureSpa 6-Pack |
|
Check Latest Price |
 POOLPURE Type S1 4-Pack |
|
Check Latest Price |
 KGC Type VI 4-Pack |
|
Check Latest Price |
 Slamate Type S1 12-Pack |
|
Check Latest Price |
 SORSWEET Type VI 12-Pack |
|
Check Latest Price |
| POOLPURE Type VI Cartridge |
|
Check Latest Price |
 Intex Type S1 29001E 12-Pack |
|
Check Latest Price |
 LYJHKJ Type VI 4-Pack |
|
Check Latest Price |
1. Best Hot Tub Filters for Inflatable Tubs: Bestway SaluSpa Type VI 60311E 2-Pack
SaluSpa Type VI Replacement Filter Cartridge for Inflatable Hot Tubs 2-Pack
Genuine Bestway part
Type VI screw-in
4.2 in diameter x 3.1 in tall
2 per pack
Pros
- OEM Bestway cartridge with denser pleats than most aftermarket copies
- Fits SaluSpa and Lay-Z-Spa housings without adaptation
- Weeks of service between rinses with no pump error codes
- Simple to install and swap
Cons
- Only two cartridges per pack so bulk buyers need multiple orders
- Pleat density is not identical to the filter supplied with some SaluSpa models
This is the cartridge Bestway itself builds for the SaluSpa and Lay-Z-Spa line, part number 60311E, and it measures 4.2 inches across by 3.1 inches tall with a plastic body. It is the safest choice if you are not certain which aftermarket clone actually fits your housing, because you are getting the same part the tub shipped with.
Owner feedback is the strongest argument for this one. Reviewers consistently report a perfect fit in SaluSpa and Lay-Z-Spa housings, crystal clear water after a rinse cycle, and noticeably longer service between changes than cheaper off-brand replacements. The rating distribution backs that up, with 81 percent of ratings at five stars across nearly 4000 reviews.
The one thing we would flag is pleat density. Some SaluSpa models were supplied with a denser pleat than this cartridge carries, so if your tub is a later production run and the water clouds faster than expected, a higher-surface-area aftermarket option may serve you better. Nothing about the fit is in question.
We also like that the media rinses clean and can be reused rather than discarded after a single soak. Over a season of moderate use, that reuse is where most of the value sits.
Who the Bestway 60311E is right for
This is the cartridge to buy if you want a guaranteed fit and do not want to cross-reference part numbers. It covers the SaluSpa and Lay-Z-Spa housings and gives you two spares so you can rotate one in the tub and one on the drying rack.
It also suits owners who already have a cleaning routine and just want a dependable OEM baseline rather than the highest possible filtration area.
Who the Bestway 60311E is not for
If you run a heavily used tub and want the largest dirt-holding capacity per cartridge, a denser aftermarket pleated option may outlast it. If your tub is an Intex PureSpa, this is the wrong family entirely and will not seat.
2. Best Hot Tub Filters for Inflatable Tubs: Volca Spares Type VI Multi-Pack
Type VI Filter Cartridge for Bestway, Lay-Z-Spa, Coleman SaluSpa
Type VI format
4.1 in by 3.1 in cartridge
Dacron fabric
1.23 lb package
Pros
- Fits soft-sided and inflatable spas snugly on the first try
- Pleats rinse clean and hold together for repeat use
- Per-cartridge cost works out well in a multi-pack
Cons
- A minority of reviews report media delaminating after a few weeks
- Some users find the fabric less dense than the factory cartridge
This is a Type VI cartridge built from dacron filter fabric at 4.1 inches by 3.1 inches, packaged at just over a pound. It is listed as compatible with Bestway, Lay-Z-Spa, Coleman, and SaluSpa housings, which makes it a broad aftermarket Type VI option.
Most owners confirm an easy, leak-free seat in soft-sided spas and good debris capture across the pleats. The rating split is 79 percent five stars with a small cluster of one-star reviews, and those negatives cluster around a single failure mode: media shedding.
The durability concern is real enough to plan around. Owners who report delamination tend to describe filters that fall apart after a few weeks of heated-water use, and some feel the fabric is thinner than what their tub came with. If you buy this, treat it as a cartridge you rinse and inspect rather than one you install and forget.
On the positive side, the pleats rinse clean and stay intact across repeated cycles for the majority of buyers, which makes the multi-pack approach work well here. Rotate two or three so each one gets a full dry cycle between installs.
Who the Volca Spares Type VI is right for
Buy this if you want a wide-compatibility Type VI cartridge for a soft-sided spa and you are comfortable rinsing it weekly. It suits owners who rotate cartridges and treat them as reusable media rather than consumables.
It is also a reasonable second cartridge to keep on hand alongside an OEM part, since the dimensions are close and both sit in the same housing family.
Who the Volca Spares Type VI is not for
If your tub sees heavy daily use or you have had media fall apart before, choose a cartridge with reinforced end caps and thicker fabric. This pick’s weakness is long-term media integrity, not fit.
3. Best Hot Tub Filters for Inflatable Tubs: Intex Type S1 29011E 6-Pack
Intex 29011E Type S1 PureSpa Easy Set Pool Spa Hot Tub Filter Replacement Cartridges (6 Filters), Blue and White
Genuine Intex part
Type S1 drop-in
3 in x 4-1/4 in each
6 per pack
Pros
- Highest rated pick in the roundup at 4.8 stars
- Covers the main PureSpa model numbers
- Owners rinse and reuse them for years of service
- Traps dirt debris and oils
Cons
- Not interchangeable with SaluSpa Type VI cartridges
- Needs monthly replacement in regularly used spas
This is the genuine Intex Type S1 cartridge sold in a six-pack, and it carries the highest average rating of anything in this roundup at 4.8 stars across more than 5000 reviews. Each cartridge measures 3 inches by 4-1/4 inches in heavy-duty dacron paper.
The compatibility list is broad for an OEM part. It covers 28403E, 28407E, 28443E, 28453E, 28421E, 28423E, and 28413E, which is most of the PureSpa line people actually own. Eighty-five percent of ratings are five stars, and owners routinely hose-clean and reuse these cartridges until the media thins out.
A few buyers note the cartridge is slightly taller than some SaluSpa S1-style parts, which is a good reminder that visually similar cartridges are not always dimensionally identical. Measure your existing cartridge before ordering if you have ever swapped brands.
Because it is a six-pack, this is also the format most owners like for rotation. One in the tub, one soaking, one drying means your cleaning session takes a few minutes instead of a full spa shutdown.
Who the Intex 29011E is right for
Any PureSpa owner who wants certainty. This is the part Intex builds, so fit tolerances are exactly what the housing was designed around, and reuse across rinse cycles stretches a single pack well beyond one season.
It is also the pick for buyers who would rather not deal with aftermarket sizing questions at all.
Who the Intex 29011E is not for
Do not buy this for a SaluSpa or Lay-Z-Spa tub. The Type S1 drop-in format will not seat in a Type VI screw-in housing, and forcing it can damage the end cap.
4. Best Hot Tub Filters for Inflatable Tubs: POOLPURE Type S1 29001E 4-Pack
POOLPURE 29001E Hot Tub Filter Replaces Type S1 PureSpa Filter 4 Pack
Replaces 29001E and 11692
4-1/4 in dia x 2-15/16 in
50 micron media
4 per pack
Pros
- Broadest Intex model coverage of the S1 cartridges here
- Dirt-locking trilobal fabric releases grit on a simple rinse
- Thicker fabric and reinforced caps stretch service life
- Certification through IAPMO testing
Cons
- Not an Intex manufactured part so tolerances differ slightly from OEM
- Manufacturer suggests replacement about every two weeks under normal use
This is a Type S1 cartridge built to replace part 29001E, with dimensions of 2-15/16 inch length and 4-1/4 inch diameter and 1-7/8 inch openings at the top and bottom. It is one of the few picks in this roundup carrying NSF/ANSI 50 certification through IAPMO testing, and the manufacturer is a Pool and Hot Tub Alliance member.
Coverage is its distinguishing feature. It lists compatibility with 29001E, 29011E, 11692, SB-h10, JPC01, and the PureSpa families from 28403E through 28453E, so it covers more Intex part numbers than any other S1 cartridge here.
The media is 4 oz thickened polyester in a trilobal structure, rated at 50 microns, with reinforced ABS end caps. Owners report a clean drop-in fit and better rinse-out than generic S1 clones, with 84 percent of ratings at five stars across more than 3300 reviews.
Who the POOLPURE Type S1 is right for
Pick this if you own an older or less common Intex part number and cannot find an OEM cartridge that lists it, or if certification matters to you and the OEM options do not carry it. The model number in the listing is simply Type S1.
Who the POOLPURE Type S1 is not for
It is not dimensionally identical to the genuine Intex part, so measure before ordering if your housing is tight. The manufacturer also recommends a two-week replacement interval under normal use, which is more frequent than most owners end up using after rinsing.
5. Best Hot Tub Filters for Inflatable Tubs: KGC Type VI 90352E 4-Pack
KGC Type VI Hot Tub Spa Filters Compatible with Coleman Saluspa 90352E 58323E 90427E, Lay-Z-Spa Hot Tub Filter Cartridge, Inflatable Hot Tub Filters Replacements (4 Pack)
Outer dia 4.2 in
Height 3.1 in
25% thicker fabric
4 per pack
Pros
- Open polypropylene core keeps water moving through the cartridge
- Seats in SaluSpa and Lay-Z-Spa housings without adaptation
- Thicker pleat media than typical budget Type VI clones
Cons
- Clogs faster than denser cartridges so cleaning is more frequent
- Not sized for Intex PureSpa S1 housings
This cartridge targets the other half of the Type VI family, the Coleman SaluSpa part numbers 90352E, 58323E, and 90427E, plus Lay-Z-Spa. It measures 4.2 inches in outer diameter, 2 inches inside, and 3.1 inches tall.
The design choice worth understanding is the flow core. It is a 50 percent open polypropylene core that supports the pleat structure while keeping water moving through the cartridge, and the filtration fabric is 25 percent thicker than standard media. Owners confirm the open core preserves circulation even as debris builds on the surface.
The tradeoff is clogging speed. Reviewers consistently note these need weekly rinsing or swapping sooner than premium cartridges, which is the direct consequence of a more open media structure. In exchange you get a cartridge that resists the collapse and delamination problems that show up in cheaper Type VI clones after a few uses.
Ratings sit at 4.6 stars with 81 percent five stars across 1474 reviews, which puts it comfortably among the better-reviewed aftermarket Type VI options.
Who the KGC Type VI is right for
This suits SaluSpa and Lay-Z-Spa owners who swim in their spa often, generate a lot of hair and sunscreen residue, and are willing to rinse weekly. The open core keeps flow up when a denser cartridge would already be restricting.
Who the KGC Type VI is not for
If you want the longest possible interval between cleanings, a denser pleat will serve you better. It also does not fit PureSpa S1 housings despite the similar shape.
6. Best Hot Tub Filters for Inflatable Tubs: Slamate Type S1 12-Pack
Slamate 12 Pack Type S1 Spa Filters for All Intex PureSpa 28429E, 28403E, 28407E, 28443E, 28453E, 28421E, 28423E, 28413E, and 28453E, 11692, SB-h10, JPC01 Swimming Pool Pump
4-1/4 in OD
2-15/16 in length
1-5/8 in openings
12 per pack
Pros
- Twelve cartridges cover a full season of weekly changes
- Dense trilobal pleating captures more debris than standard cloth
- Washable and reusable when maintained
Cons
- Some buyers find the media dirties quickly and is hard to rinse back
- Not a genuine Intex part so sizing differs marginally from OEM
- Lowest review count among the S1 options
This is a bulk Type S1 pack measuring 4-1/4 inches in outside diameter and 2-15/16 inches in length, with 1-5/8 inch holes top and bottom. The compatibility list covers 28429E, 28403E, 28407E, 28443E, 28453E, 28421E, 28423E, 28413E, 11692, SB-h10, and JPC01.
Media is trilobal non-woven fabric with a polypropylene flow core and chlorine-resistant reinforced end caps, and the claim is dense pleating that captures roughly three times more contaminant volume than standard fabric. Owners of Intex tubs confirm the cartridges fit and survive repeated washing.
The reason to buy twelve at once is the rotation cycle. If you are washing cartridges weekly, a twelve-pack covers a full season without a second order, and the per-filter cost works out better than any smaller pack in this roundup.
The honest limitation is the cleaning experience. A minority of buyers report the media dirties quickly and resists rinsing back to white, and the 485-review count is the smallest of any S1 option listed here, so long-term durability is less proven than on the higher-volume picks.
Who the Slamate Type S1 is right for
Owners of a PureSpa who use the tub weekly and want a full year of spares on hand without reordering. The bulk quantity and the rotation workflow are the deciding factors for most buyers here.
Who the Slamate Type S1 is not for
If your tub sees light seasonal use, twelve is far more than you need. If you hate the rinse-and-soak process, expect more effort than with a denser OEM paper cartridge.
7. Best Hot Tub Filters for Inflatable Tubs: SORSWEET Type VI 12-Pack
SORSWEET 12 Pack Type VI Hot Tub Filter Cartridge Compatible with Lay-Z-Spa, Coleman SaluSpa 90352E 58323 90427E
Type VI format
4.13 in x 4.13 in x 3.1 in
Reinforced plastic caps
12 per pack
Pros
- Twelve cartridges suit year-round spa use
- Dirt releases easily when rinsing so cartridges can be reused
- Highest share of five-star ratings among the twelve-pack options
Cons
- Bulky pack is unnecessary for occasional spa owners
- Non-OEM part with no SaluSpa or Intex certification
This is a Type VI cartridge at 4.13 inches by 4.13 inches by 3.1 inches, listed for Coleman SaluSpa, Lay-Z-Spa, and other Type VI inflatable tubs. The pack contains twelve, and the same line is offered in six, twelve, and twenty-four counts for owners who want to size up later.
Construction is reinforced plastic end caps with quality fiber pleats, and owners report the media releases dirt easily enough during rinsing that the cartridges stay reusable across many cycles. SaluSpa and Lay-Z-Spa owners describe a clean fit and water that stays clear between changes.
At 86 percent five-star ratings across 1151 reviews, the satisfaction is concentrated in the bulk value rather than in any single performance figure. Nobody is claiming this is a filtration upgrade. It is a supply solution for owners who would otherwise be ordering pairs.
The absence of certification is worth noting if you are cautious about materials in heated water. It is an off-brand part with no SaluSpa or Intex certification, so the media and cap compounds are the manufacturer’s own.
Who the SORSWEET Type VI is right for
SaluSpa and Lay-Z-Spa owners with a working three-filter rotation who want a year’s worth of spares delivered at once. It suits tubs in regular use where cartridges are swapped on a fixed schedule.
Who the SORSWEET Type VI is not for
Occasional users and seasonal owners will end up storing most of the pack. If certification or exact OEM tolerances matter, choose an Intex or Bestway part instead.
8. Best Hot Tub Filters for Inflatable Tubs: POOLPURE Type VI 90352E Cartridge
Type VI Hot Tub Filter Cartridge Replaces Coleman SaluSpa Hot Tub Filters
3 1/8 in length
4 1/4 in diameter
Trilobal fabric
2 in openings
Pros
- Pleats rinse clean and stay white in hard water
- Owners report one cartridge lasting three months of daily use
- Seamless fit in SaluSpa and Lay-Z-Spa housings
- No noticeable flow restriction versus the factory filter
Cons
- Pleat density is still slightly less than the supplied cartridge
- Reuse is limited so some buyers swap rather than wash
This is the aftermarket Type VI option we keep coming back to for SaluSpa owners. It measures 3-1/8 inch in length and 4-1/4 inch in diameter with 2 inch openings, and it covers 90352E, 58323E, 58323, 58324, and 90427E along with Bestway, Lay-Z-Spa, and Coleman housings.
The fabric is trilobal with a dirt-locking structure, listed at 25 percent thicker than standard with a reinforced centre support and chlorine-resistant end caps. The manufacturer claims the thicker media and support extend service life by 20 to 30 percent.
Owners call it the best aftermarket Type VI they have tried, with 3202 reviews at 4.7 stars and 82 percent five-star ratings. Rinse-out performance is the repeated theme, including in hard water, and several mention no flow restriction compared with the factory filter.
There is one consistent caveat across reviews: pleat surface area is still a step below the cartridge supplied with the tub. It does not hurt fit or function, but if you are chasing maximum dirt holding you may see a shorter interval than the OEM part.
Availability in four, six, twelve, and sixteen counts means you can buy a small pack to test the fit and a larger one later once you have confirmed it works in your housing.
Who the POOLPURE Type VI is right for
This is the pick for someone who wants to move off OEM pricing without losing measurable performance. SaluSpa and Lay-Z-Spa owners who already have a cleaning routine tend to get the most out of it.
Who the POOLPURE Type VI is not for
Skip it if you need a certified part or if your previous cartridges failed from media collapse rather than from clogging. It is also the wrong format for any PureSpa S1 housing.
9. Best Hot Tub Filters for Inflatable Tubs: Intex Type S1 29001E 12-Pack
Intex PureSpa Type S1 Replacement Filter Cartridges (12 Pack) | 29001E
Genuine Intex part 29001E
3 in x 4-1/4 in each
12 per pack
Dacron paper
Pros
- Largest review base of any product in this roundup
- Genuine Intex part guarantees fit in PureSpa pumps
- Twelve cartridges let you rotate while cleaning
Cons
- Highest cost per cartridge among the OEM Intex options
- Monthly replacement cycle keeps ownership cost above generic S1
This is part 29001E in a twelve-pack, the default Intex Type S1 cartridge and the one with by far the most owner history behind it at nearly 14,000 ratings. Each cartridge measures 3 inches by 4-1/4 inches in heavy-duty dacron paper.
Long-term owners treat it as the reference cartridge: exact fit, dependable filtration, and enough spares to rotate while one is being cleaned. Eighty-four percent of ratings are five stars, which is about as consistent as this category gets.
Being the OEM part, it is also the one that sets the compatibility baseline. If your existing cartridge says 29001E, this is the guaranteed match, and it will fit every PureSpa model the line produced.
Who the Intex 29001E is right for
PureSpa owners who want the default part and already know their tub takes 29001E. The twelve-pack is well suited to rotation and to owners who would rather not reorder mid-season.
If your spa is heavily used and you want to try a denser aftermarket media later, this is also a good baseline to measure against.
Who the Intex 29001E is not for
The cost per cartridge is higher than the aftermarket S1 options, and the monthly replacement cycle adds up over years. If you are on a tight replacement budget and your chemistry is consistent, a generic S1 multi-pack is the more economical path.
10. Best Hot Tub Filters for Inflatable Tubs: LYJHKJ Type VI 4-Pack
LYJHKJ Type VI Inflatable Hot Tub Filters Cartridge and SPA Filters Replacements Compatible with Coleman Saluspa 90352E 58323 90427E, Lay-Z-Spa Hot Tub Filter Cartridge, 4 Pack
Covers 90352E and 60311E
Chlorine-resistant end caps
Trilobal woven fiber
4 per pack
Pros
- Broadest listed compatibility for SaluSpa part numbers
- Chlorine-resistant end caps hold up in heated spa water
- Pleated media scrubs clean and can be reused several times
Cons
- Lowest average rating among the picks at 4.5 stars
- Smallest review base so long-term durability is less proven
This Type VI cartridge lists the widest set of Coleman part numbers of anything here: 90352E, 58323E, 58323, 58324, 90427E, 90363E, and 60311E, plus Lay-Z-Spa. That matters if you inherited a tub with no paperwork and need a cartridge that is likely to seat.
The media is impregnated woven trilobal fiber with dense pleating and a chlorine-resistant end cap, and the claim is a five-fold increase in contaminant capture against standard media. Owners of SaluSpa and Lay-Z-Spa models confirm the cartridge fits and rinses well.
The caution here is the evidence base. At 170 ratings and 4.5 stars, this is the lowest-rated and least-reviewed pick in the roundup, which means the fit claims are well supported while the long-term durability claims are not. The rating distribution includes a 4 percent one-star share, the largest here.
Treat it as a shortlist candidate rather than a set-and-forget cartridge. Buy the four-pack, install one, and judge the media after a few weeks of heated-water use before committing to it as your only supply.
Who the LYJHKJ Type VI is right for
Owners with an older SaluSpa or Lay-Z-Spa whose part number is not clearly documented, or anyone who wants one cartridge listing to cover several possible tub generations. The chlorine-resistant cap is a plus in permanently heated water.
Who the LYJHKJ Type VI is not for
Do not make this your only supply for a heavily used tub. With the smallest sample of owner reports in the roundup, a higher-reviewed cartridge is the safer long-term bet.
How to Choose Hot Tub Filters for Inflatable Tubs
Choose by cartridge family first, then by measurement, then by media. Get the family right and almost everything else follows; get it wrong and no amount of filtration area will help you.
Measure before you buy. Pull the existing cartridge out of the housing and take three measurements. Measure the outer diameter edge to edge, measure the cap-to-cap length with the handle and any fittings excluded, and note whether the top and bottom are open or closed. Round to the nearest 1/8 inch and compare against the listing rather than eyeballing it. Also check the hole openings, because a cartridge with a 1-7/8 inch opening will not pass through a 2 inch collar even if the diameter matches.
Know the two families. Type VI is the screw-in format used by Coleman SaluSpa and Lay-Z-Spa, and cartridges usually measure around 4.2 inches in diameter by 3.1 inches tall. Type S1 is the drop-in format used by Intex PureSpa, typically 4-1/4 inches in diameter by 2-15/16 or 3 inches long. These are not interchangeable, and the visual similarity is the reason so many orders are returned.
Look at media, not just area. Filtration area in square feet is only half the story. A cartridge with a high advertised area but thin fabric will clog in days, while thicker trilobal media holds its flow longer. Several picks here specify 4 oz thickened polyester or fabric 25 percent thicker than standard, and that is the number worth comparing.
Check the core. An open polypropylene flow core keeps water moving through a loaded cartridge. If your tub is used daily, that open core is a real advantage even if the pleat count looks lower on paper.
Multiply by rotation, not by price. A six or twelve pack costs more up front but lets you run a proper rotation with one cartridge in the tub, one soaking, and one drying. Forum consensus across hottub owner groups is that buying in bulk and rotating three at a time is the single biggest change people make to cartridge life. Budget accordingly instead of chasing the cheapest single unit.
Decide on OEM versus aftermarket. The OEM cartridge guarantees fit tolerances. The aftermarket cartridge costs less per unit and often carries thicker media. The gap between them is usually pleat density rather than fit, and owners who bought OEM report longer intervals while owners on aftermarket report better value. If a listing names specific part numbers, that is a much stronger fitment claim than a page that says universal fit.
One more note: several CosySpa and Lay-Z-Spa listings carry a warranty clause stating the filters must be used alongside chemical kits. Running a tub without sanitizer treatment will degrade any cartridge quickly, and it can affect how the tub itself is covered. Our hot tub covers guide covers the other half of protecting the tub between uses.
Hot Tub Filters for Inflatable Tub Brands: Quick Compatibility Map
This map matches the most common inflatable tub brands to the cartridge part number they take. Confirm against the number printed on your existing cartridge before ordering.
Coleman SaluSpa: Type VI screw-in cartridge, part 60311E for many models, with 90352E, 58323, 58324, 90427E, and 90363E also appearing across the line. The housing format is the deciding factor, not the marketing name.
Lay-Z-Spa and CosySpa: Type VI screw-in cartridge, commonly 90352E or 58323E. These share the SaluSpa housing family, so most Type VI cartridges cross over, but check the length and thread before installing.
Intex PureSpa: Type S1 drop-in cartridge, part 29001E or 29001WL, covering model families 28403E, 28407E, 28413E, 28421E, 28423E, 28429E, 28443E, and 28453E. Older units also use 11692, SB-h10, and JPC01.
Other Intex units: 29011E is the six-pack form of the same Type S1 cartridge, so the dimensions match and the choice is pack size rather than fit.
Generic Type VI tubs: If the cartridge is roughly 4.2 inches in diameter and 3.1 inches tall with a screw-in thread, match on diameter, length, and thread size. Do not rely on shape alone.
Two common fitment traps are worth naming. First, the same brand name can use a screw-in cartridge in one model year and a drop-in in another, so the brand alone is not enough. Second, Intex cartridges are sometimes described as S1-style alongside SaluSpa parts of similar size, but the opening sizes differ and the cartridge will not pass the collar. Measure, then order.
How to Clean and Rotate Hot Tub Filters for Inflatable Tubs
How often should I change the filter in an inflatable hot tub? The honest answer depends on use, but a cartridge that is rinsed weekly and rotated through a three-unit set typically needs replacing every two to three months in a regularly used tub, and monthly in a heavily used one.
1. Rinse after every use. Take the cartridge out, hose it from the outside in until the media runs white, and never let it dry folded or bent. Owners who hose weekly report cartridges lasting three months of daily use instead of weeks.
2. Soak monthly in a purpose-built cleaner. A filter cleaner designed for spa cartridges dissolves oils and sunscreen residue that rinsing alone leaves behind. A forum comparison thread on r/hottub found a Pleatco cartridge held up for a full year with a soak routine, while a budget cartridge in the same conditions had slightly cloudy water after six weeks. That difference was filter life, not chemistry.
3. Rotate three cartridges. One in the tub, one soaking, one drying flat. The dry time matters as much as the cleaning, and this is the habit that most extends cartridge life. Twelve-packs in this roundup exist largely to make rotation practical.
4. Replace on a schedule, not on appearance alone. Manufacturers across these listings suggest intervals from two weeks to monthly depending on the media. Pick the interval that matches your usage and set it in your calendar rather than waiting for the water to change.
5. Discard when the media fails structurally. Replace the cartridge when pleats are visibly torn or thinning, when end caps are cracked or loose, when the media delaminates or sheds flakes, or when the pleats no longer spring back after a rinse. A cartridge that stays collapsed will restrict flow and starve the pump.
On vinegar and baking soda. White vinegar and a mild detergent are fine for routine rinsing of a cartridge, and a dilute vinegar soak helps with scale. Baking soda is not a substitute for filter cleaner, and mixing cleaning products in a closed tub can produce gas. Never combine cleaners, and never use a cartridge cleaner in the tub water itself.
Why is the water still cloudy with a new filter? Filtration and chemistry are separate systems. A fresh cartridge removes particulate but does nothing about sanitizer level, pH, or dissolved minerals, and a heavily loaded tub with an undersized cartridge can cloud faster than one cartridge can clear. Test sanitizer and pH first, then run the filter continuously for a full cycle, and only then suspect the cartridge. If the water clears after a chemical adjustment with the same filter in place, the filter was never the problem. Accessory-wise, our hot tub step picks cover safe entry for maintenance work.
Upgrades beyond the cartridge. If your tub feels undersized for its water volume, the options most owners discuss are filter balls or sock filters for the same housing, a larger pleated cartridge, or an external filter plumbed to the tub. An external paper or sand filter is a bigger project and adds plumbing points that can leak, but it moves the filtration load out of the tub entirely. Filter balls and polyfill are the cheapest intervention and are usually enough to take the edge off a daily-change cartridge.
Off-season storage. Before winterizing, clean the cartridge, dry it fully, and store it flat away from direct sunlight. Bleached or sun-damaged media degrades faster than you would expect, and a cartridge that sat in a cold garage all winter often starts its first season already weakened.
Frequently Asked Questions
How often should I change the filter in an inflatable hot tub?
Rinse the cartridge weekly and replace it roughly every two to three months in a regularly used inflatable spa, or monthly in a heavily used one. Manufacturer guidance across these cartridges ranges from about two weeks for open-core aftermarket media to about one month for OEM dacron paper. Running a three-cartridge rotation so one is always soaking or drying roughly doubles the effective life of each unit before you notice any drop in clarity.
How do I know which filter I need for my hot tub?
Match your tub brand to the cartridge family, then verify by measurement. Coleman SaluSpa and Lay-Z-Spa use Type VI screw-in cartridges, usually 4.2 inches in diameter by 3.1 inches tall. Intex PureSpa uses Type S1 drop-in cartridges, usually 4-1/4 inches in diameter by 2-15/16 or 3 inches long. Measure the outer diameter, the cap-to-cap length excluding the handle, and the hole openings, then round to the nearest 1/8 inch.
What type of filter cartridge does a SaluSpa hot tub use?
A SaluSpa hot tub uses a Type VI screw-in filter cartridge, with part 60311E on many models and part numbers 90352E, 58323, 58324, 90427E, or 90363E appearing across the line. Cartridges are roughly 4.2 inches in diameter by 3.1 inches tall. Read the number printed on your existing cartridge before ordering, because the same brand name can use different cartridges across model years.
How long do inflatable hot tub filters last?
A cartridge rinsed weekly and rotated through a three-unit set typically lasts two to three months in a regularly used inflatable spa. Some owners with a proper soak routine report a cartridge lasting a full year, while heavily used tubs with open-core aftermarket media can need a change every two weeks. Media thickness matters more than advertised filtration area: thin fabric clogs fast, thicker trilobal media holds flow far longer.
What is the best solution to clean a pool filter cartridge?
Hose the cartridge from the outside in until the media runs white, then soak it monthly in a cleaner made for spa filter cartridges to dissolve oils and sunscreen residue. Let it dry completely and flat between uses, and never let pleated media dry folded. A dilute white vinegar soak helps with mineral scale, and a mild detergent is fine for routine rinsing. Never combine two cleaning products, since some spa cleaners react badly when mixed.
Our Final Pick for Hot Tub Filters for Inflatable Tubs
The Bestway SaluSpa Type VI 60311E 2-pack is our pick for hot tub filters for inflatable tubs, because an OEM part is the one place where fit, media, and longevity are guaranteed rather than probable. Intex PureSpa owners should take the genuine 29001E twelve-pack for the same reason, and everyone else can use the measurement protocol in the buying guide above to confirm their family before ordering.
Whatever you choose, buy a multipack and run a three-cartridge rotation. That habit does more for your water clarity than any single cartridge swap, and it is what owners on hottub forums consistently report after a season of use. As you are choosing accessories, our inflatable hot tub guide covers the rest of the setup.