Pool Equipment
Spa filter cartridges: check the type before the price
Buy Type S1 for an Intex PureSpa and Type VI for a Bestway, Lay-Z-Spa or Coleman SaluSpa. They look similar, they do not interchange, and that one fact causes more wasted orders in this category than anything else.
Heads up: we earn a commission if you buy through the links on this page, at no extra cost to you. It never decides the ranking — here is how we pick and here is the full disclosure. Prices are checked automatically; last verified October 11, 2026.
Quick picks
Segmented before it is ranked — the right answer depends on which of these you actually are. Tap any row for the full write-up.
Intex PureSpa, genuine part
The real Type S1 in a three-pack. Fit is not a question and the housing seal is right.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | Intex Type S1 Spa Filter Cartridge, 3-Pack The genuine Type S1 in the smallest sensible quantity. A hot tub eats cartridges far faster than a pool does, and buying one at a time is how people end up running a dirty filter. | An Intex PureSpa, bought from the brand that made the tubA few weekends | 7.6out of 10 |
Intex PureSpa, cost per cartridge
Six that fit the same housing for less than three genuine ones. On a consumable nobody publishes a filtration spec for, quantity is the comparison you can actually check.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  POOLPURE Type S1 Spa Filter, 6-Pack Six Type S1 cartridges for less than three genuine ones. On a consumable with no published filtration spec on either side, quantity is the argument that can actually be checked. | Running a tub hard without rationing cartridgesA few weekends | 8.3out of 10 |
Bestway, Lay-Z-Spa or Coleman SaluSpa
Type VI covers the whole Bestway family. This is the half of the market the S1 cartridges do not fit.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  Type VI Spa Filter Cartridge for Bestway, Lay-Z-Spa and Coleman SaluSpa Type VI is the Bestway family's cartridge and it is not interchangeable with Type S1. Getting this wrong is the most common spa parts mistake there is, and the two look similar enough to make it easy. | Anything that is not an Intex — the other half of the marketA few weekends | 8.0out of 10 |
The thing that makes cartridges last
A hose rinses grit off. It does nothing about the body oils that actually clog a spa cartridge, and oils are most of the load at 102 degrees.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  AquaDoc Hot Tub and Pool Filter Cleaner Spray, 16 oz A hose rinses grit off a cartridge; it does nothing about the body oils and lotions that clog the pleats. On a hot tub that distinction matters far more than it does on a pool. | Getting oils out of a cartridge a hose cannot touchA few weekends | 8.2out of 10 |
The short version
- Two families, no crossover. Intex PureSpa takes Type S1. Bestway, Lay-Z-Spa and Coleman SaluSpa take Type VI.
- Divide pack price by count. Pack sizes run from 2 to 12 at similar headline prices, so cost per cartridge varies by more than three times.
- No maker publishes a micron rating. Not the genuine parts, not the third-party ones. Filtration cannot be compared in this category.
- Oils are the load, not grit. At 102 degrees with four people in 200 gallons, a hose rinse does not touch what is actually clogging the pleats.
The fit question, which is the whole page
Our pool cartridge roundup is about filtration area and pleat count, because pool cartridges publish those. Spa cartridges publish almost nothing, so the useful page is a different one: which part fits your tub, and what a cartridge actually costs once you divide by the pack.
| Cartridge type | Fits | Does not fit | Common pack sizes |
|---|---|---|---|
| Type S1 | Intex PureSpa | Bestway, Lay-Z-Spa, Coleman SaluSpa | 1, 3, 4, 6, 12 |
| Type VI | Bestway, Lay-Z-Spa, Coleman SaluSpa | Intex PureSpa | 2, 4, 6, 12 |
Cost per cartridge, because pack prices are not comparable
This is the only arithmetic in the category that can be done honestly, and it changes the ranking completely.
| Pick | Type | Pack | What you are buying on |
|---|---|---|---|
| Intex genuine | S1 | 3 | Brand fit confidence |
| POOLPURE | S1 | 6 (also sold as 4) | Cost per cartridge |
| Type VI generic | VI | 2 (also 4, 6, 12) | The only option for a Bestway family tub |
The reason this matters more on a hot tub than on a pool is the replacement rate. A pool cartridge is a seasonal item. A spa cartridge used weekly is a few-weeks item, so you are not buying one cartridge, you are buying a supply — and a six-pack at a lower unit price is a genuinely different purchase from a single at a convenience price.
Why a spa eats cartridges
A 200-gallon tub with four people in it has roughly the bather load per gallon of a backyard pool with a hundred people in it. Our swimmer load page does that arithmetic for a pool; on a tub the same effect is concentrated into a volume small enough to notice within hours.
What arrives with people is mostly oil: skin oils, lotion, hair product, deodorant. Those do not rinse out. They press into the pleats and stay there, and the visible result is a cartridge that looks clean after hosing and still passes cloudy water. That is the entire case for a cartridge cleaner on this page, and the reason it is a pick rather than an afterthought.
What we will not rank these on
Filtration. There is no micron rating published for any cartridge in this category, from Intex, Bestway or any of the third-party makers, so any claim that one filters finer than another would be invented. We have looked and it is not there.
What that leaves is honest and still useful: does it fit, how many do you get, and what does one cartridge cost. The genuine Intex part wins the first outright. The third-party multipacks win the third by a wide margin. Which of those you weight is a real decision and not one we can make for you.
When the cartridge is not the problem
If a fresh cartridge goes cloudy within a day, you have a water problem rather than a filter problem, and the answer is a water change rather than another cartridge. Our hot tub water change page covers how often that should be happening and the arithmetic behind it.
And if the tub is running through winter, the cartridge load does not drop just because the air is cold — usage usually goes up. Our winter hot tub guide covers the rest of what changes between October and March.
The picks, in full
Scores are our own reading of published specifications. They are not test results — we have not tested these products and we do not claim to.
Pick #1 · An Intex PureSpa, bought from the brand that made the tub
Intex Type S1 Spa Filter Cartridge, 3-Pack
Intex
The genuine Type S1 in the smallest sensible quantity. A hot tub eats cartridges far faster than a pool does, and buying one at a time is how people end up running a dirty filter.
Key specs
- Type
- Type S1, published
- Fits
- Published for Intex PureSpa inflatable hot tubs
- Quantity
- 3-pack, published
- Media
- Pleated paper, published as Dacron paper on Intex's heavy-duty variant
- Micron rating
- Not published — no spa cartridge in this category publishes one
- Washable
- Rinseable between changes; not indefinitely reusable
How it scoresour reading of published specs, not a test result
- Sizing fit
- 9.5
- Running cost
- 6.0
- Maintenance
- 7.5
- Build
- 7.0
- Value
- 7.0
Overall 7.6 / 10
What works
- Genuine part, so the fit in the Intex housing is not a question
- Three at a time matches how fast a tub actually loads a cartridge
- Sold alongside Intex's own heavy-duty Dacron version if you want to step up
- The cheapest way to stop running a hot tub on a gray filter, which is the single most common cause of cloudy spa water
What doesn't
- No micron rating published, which is true of the whole category and means filtration cannot be compared at all
- Three cartridges is a few weeks of heavy use, not a season
- Paper media degrades with every rinse, so "washable" has a short ceiling
- Costs more per cartridge than the generic multipacks that fit the same housing
Skip it if: Running a tub used by a crowd. At four people in 200 gallons the cartridge is the bottleneck, and no cartridge fixes a bather load problem — that is a water-change question.
What it costs to run: Cost per cartridge is the number to compare, not pack price. Genuine Intex runs well above the generic six and twelve packs; whether that is worth it is a fit-confidence question, because nothing about filtration is published either way.
A few weekends: Fine for a heatwave and a toddler. Treat it as consumable, not as a pool — it will not survive a winter in the yard.
Pick #2 · Running a tub hard without rationing cartridges
POOLPURE Type S1 Spa Filter, 6-Pack
POOLPURE
Six Type S1 cartridges for less than three genuine ones. On a consumable with no published filtration spec on either side, quantity is the argument that can actually be checked.
Key specs
- Type
- Replaces Type S1, published; listed as replacing Intex 29001E
- Quantity
- 6-pack, published
- Fits
- Published for Intex PureSpa models
- Media
- Pleated paper
- Micron rating
- Not published
- Also sold as
- A 4-pack at a published lower price
How it scoresour reading of published specs, not a test result
- Sizing fit
- 8.0
- Running cost
- 9.5
- Maintenance
- 7.5
- Build
- 6.5
- Value
- 9.0
Overall 8.3 / 10
What works
- Six cartridges is a realistic season on a tub used weekly, in one order
- Costs less per cartridge than the genuine three-pack by a wide margin
- Having spares is what actually keeps a clean cartridge in the housing
- Published explicitly against the Intex part number rather than a vague compatibility claim
What doesn't
- No micron rating published — same gap as the genuine part, so you are comparing on price and fit only
- Third-party pleat quality and end-cap fit vary between production runs in a way a brand part does not
- Paper media, so the same short washable ceiling applies
- A six-pack stored badly in a damp garage is a six-pack of damp cartridges
Skip it if: Settling the filtration question. Nobody in this category publishes a micron rating, so no cartridge here can be shown to filter better than another. Buy on fit and on cost per cartridge, and be honest that is all the data there is.
What it costs to run: This is the cost-per-cartridge pick. Divide pack price by count before comparing anything in this category, because pack sizes run from one to twelve and headline prices are not comparable.
A few weekends: Fine for a heatwave and a toddler. Treat it as consumable, not as a pool — it will not survive a winter in the yard.
Pick #3 · Anything that is not an Intex — the other half of the market
Type VI Spa Filter Cartridge for Bestway, Lay-Z-Spa and Coleman SaluSpa
Generic
Type VI is the Bestway family's cartridge and it is not interchangeable with Type S1. Getting this wrong is the most common spa parts mistake there is, and the two look similar enough to make it easy.
#ad how this is funded · price as of October 11, 2026
Key specs
- Type
- Type VI, published
- Fits
- Published for Bestway, Lay-Z-Spa and Coleman SaluSpa inflatable hot tubs
- Does NOT fit
- Intex PureSpa, which uses Type S1 — different housing, different cartridge
- Quantity
- Sold from 2-packs up to 12-packs across listings
- Media
- Pleated paper
- Micron rating
- Not published
How it scoresour reading of published specs, not a test result
- Sizing fit
- 8.5
- Running cost
- 8.5
- Maintenance
- 7.5
- Build
- 6.5
- Value
- 8.5
Overall 8.0 / 10
What works
- Covers the entire Bestway/Coleman/Lay-Z-Spa family with one part number
- Widely stocked in several pack sizes, so cost per cartridge can be optimized
- Cheap enough that replacing rather than rinsing is a realistic habit
- The listing names the three brand families explicitly rather than claiming universal fit
What doesn't
- No micron rating published, same as every cartridge in this category
- Easily confused with Type S1 — they are not interchangeable and the tub will not tell you
- Third-party only in most pack sizes; Bestway's own part is harder to find in quantity
- Paper media with the usual short rinse ceiling
Skip it if: Fitting an Intex tub. If your hot tub is a PureSpa this is the wrong cartridge, and no amount of pushing will make it seal. Check the tub brand before the pack size.
What it costs to run: Same arithmetic as the Intex side: divide by count. Pack sizes here run from 2 to 12 at headline prices that look similar, so cost per cartridge varies by more than three times across the listings.
A few weekends: Fine for a heatwave and a toddler. Treat it as consumable, not as a pool — it will not survive a winter in the yard.
Pick #4 · Getting oils out of a cartridge a hose cannot touch
AquaDoc Hot Tub and Pool Filter Cleaner Spray, 16 oz
AquaDoc
A hose rinses grit off a cartridge; it does nothing about the body oils and lotions that clog the pleats. On a hot tub that distinction matters far more than it does on a pool.
#ad how this is funded · price as of October 11, 2026
Key specs
- Volume
- 16 oz, published
- Form
- Spray-on degreaser for cartridges, published
- Use
- Published for hot tub and pool cartridges
- Contact time
- Not published on the listing
- Dilution
- Ready to use as a spray
How it scoresour reading of published specs, not a test result
- Sizing fit
- 8.0
- Running cost
- 9.0
- Maintenance
- 8.5
- Build
- 7.0
- Value
- 8.5
Overall 8.2 / 10
What works
- Targets the thing a hose cannot: oils and lotion residue pressed into the pleats
- Spray format means no bucket soak, which is the step people skip
- One bottle covers many cleanings, so cost per clean is small
- Extends cartridge life, which on a tub chewing through Type S1 or VI is the real saving
What doesn't
- No contact time or dilution published, so technique is left to you
- A degreaser is not a substitute for replacement — pleats still break down
- Does nothing about calcium scale, which needs an acid rinse instead
- Cleaned cartridges must dry fully before reuse, and nothing on the bottle says so
Skip it if: Rescuing a dead cartridge. Once the pleats are gray through and no longer spring back, no cleaner brings filtration back; that is a replacement, and the multipacks on this page exist for that reason.
What it costs to run: The case for it is cartridge life. If a bottle doubles how long a pack of cartridges lasts on a heavily used tub, it pays for itself in one pack.
A few weekends: Fine for a heatwave and a toddler. Treat it as consumable, not as a pool — it will not survive a winter in the yard.
Pick #5 · Hard water, and people who already own Intex
Intex PureSpa Inflatable Hot Tub
Intex
The direct alternative, and the built-in hard water treatment is a genuine point of difference rather than a marketing one if your fill water is hard.
#ad how this is funded · price as of October 11, 2026
Key specs
- Capacity
- 4 people (28429EP)
- Size
- 77in round x 28in
- Water treatment
- Built-in hard water treatment system
- Included
- Energy-efficient spa cover, 2 headrests, LED light
- Jets
- Bubble massage — air, not water jets
- Running cost
- Not published
How it scoresour reading of published specs, not a test result
- Running cost
- 5.5
- Build
- 7.5
- Value
- 7.8
Overall 7.5 / 10
What works
- Built-in hard water treatment is a real advantage on hard fill water
- Insulated cover included rather than sold separately
- Shares the Intex accessory ecosystem if you already own an Intex pool
- Headrests and light included, which are usually add-ons elsewhere
What doesn't
- Air bubbles rather than water jets, same as the category
- Four people is a genuine four, not an optimistic one
- Cartridges need changing often at spa temperatures and bather loads
- Wattage is not published, so the running cost cannot be computed before purchase
Skip it if: Cold-climate winter use without serious attention to the cover and the ground under it. These are insulated, not immune.
What it costs to run: Same shape as the rest of the category: the electricity dwarfs the purchase over a year. The one lever you control is whether the cover goes back on every single time.
Several seasons: Buy-once. Built and warranted to come back out of the box for a few years, if you store it properly.
Specs from: Intex PureSpa 28429EP — current Amazon listing and published specifications
Pick #6 · The default inflatable hot tub
Coleman SaluSpa Inflatable Hot Tub
Coleman (Bestway)
The one most people end up with, and reasonably so. Insulated cover and wall are the specs worth paying for, because everything expensive about owning one of these is heat you paid for and then lost.
#ad how this is funded · price as of October 11, 2026
Key specs
- Capacity
- 4 to 6 people, depending on SKU
- Size
- 71in or 77in round x 28in, per model
- Jets
- 140 AirJets on current models
- Cover
- EnergySense insulated cover included
- Cold weather
- Freeze Shield on current models
- Running cost
- Not published — depends on your rate and ambient temperature
How it scoresour reading of published specs, not a test result
- Running cost
- 5.5
- Build
- 7.5
- Value
- 8.0
Overall 7.6 / 10
What works
- Insulated cover and wall are the features that actually govern the running cost
- No installation, no permit conversation, no groundwork beyond a level base
- Packs away, which matters if the yard has one usable corner
- Widely stocked, so replacement filters and parts are easy to find
What doesn't
- Air jets, not water jets — this is bubbles rather than massage, and people expect the latter
- Heating is slow by design; you plan around it rather than deciding on the day
- Filter cartridges are a frequent consumable at spa bather loads
- Vinyl in constant hot water ages faster than the same vinyl in a pool
Skip it if: Anyone expecting hydrotherapy jets. It is a warm bubbling tub, and that is a different product from a hard-shell spa.
What it costs to run: The purchase is the small number. A hot tub is heated 24/7 rather than seasonally, so the electricity is the real commitment and it is entirely a function of your rate, your cover discipline and your climate. Nobody publishes a national figure and we will not invent one.
Several seasons: Buy-once. Built and warranted to come back out of the box for a few years, if you store it properly.
Specs from: Coleman SaluSpa — current Amazon listing and published specifications
Questions people actually ask
What filter does my inflatable hot tub take?
How often should you change a hot tub filter cartridge?
Can you wash and reuse spa filter cartridges?
Which spa cartridge filters best?
Does a dirty cartridge make hot tub water cloudy?
Sources
Read next
- Equipment, sized to your pool and costed by the wattPumps, filters, vacuums, heaters and ladders - matched to your gallons and priced by what they draw.
- Filter cartridges: the consumable that decides whether your water is clearGetting the right cartridge for your pump, how many a season takes, and why buying singly is where this line gets expensive.
- Filter cartridges: the consumable nobody budgets forThe replacement interval, the rinse-versus-scrub question, and how the cartridge treadmill compares with a sand filter across a season.
- Inflatable hot tubs, judged on the bill rather than the bubblesThe two inflatable hot tubs worth shortlisting, compared on insulation and cover rather than jet count, plus the running cost nobody publishes.
- A hot tub is not a small poolBromine against chlorine for an inflatable hot tub, what a starter kit actually contains, and why the testing cadence is the thing that changes.
- Hot tub water change: the arithmetic says two weeksWhy an inflatable hot tub needs its water changed in weeks rather than months, the arithmetic behind it, and what to do at each change.
- Inflatable hot tub running cost: the bill is a winter billThe electricity arithmetic for an inflatable hot tub held at temperature through winter, built from published heater wattage and current published rates.
- An inflatable hot tub in winter: never let it freeze, cover everything elseWhat changes when an inflatable hot tub runs through the cold months - the loss-side purchases that pay for themselves, and the freeze failure that ends the tub.
- Bather load: the variable that explains your worst weeksWhy gallons per swimmer is the number that matters, what a busy afternoon costs you in chlorine, and the routine that absorbs it.