14 Great Hot Tub Replacement Filters For Sale Online

You’ve removed your hot tub filter and noticed it’s grimier than usual.

After soaking it like normal, the filter media is starting to fall apart.

There’s no way this filter is going to do its job anymore, and you’re destined for a life of dirty hot tub water if you don’t do something fast.

It’s time for a hot tub filter replacement.

The filter is arguably the most important part of your hot tub, and keeping it functioning properly is crucial to the whole spa system. When you make sure to keep up with your hot tub replacement filters, you are taking a huge step toward ensuring the lifespan of your hot tub.

However, when shopping for replacement hot tub filters, you might feel a little overwhelmed by all the different options available. You might not know for sure which one is best for your needs, and you might have no idea where to start looking.

That’s what this article is here for. Below, you’ll find a list of the top 14 best hot tub replacement filter cartridges to make shopping easier than ever for you. You’ll be able to choose the perfect one for your specific spa model, and in no time, you’ll be able to replace that worn out old filter with a new, clean cartridge instead.

Read on to learn all about the best filter replacements on the market today and see for yourself which one can do the best job for you.

Why are Hot Tub Filters Important?

When you notice your current hot tub filter isn’t working the way it should, you might be tempted to just remove it and not bother with purchasing a replacement. If you’re considering this, you might want to take a step back and think about just how important a hot tub filter really is to the functionality of the entire spa system. Familiarize yourself with the details below before you get started searching for the perfect replacement filter.

a hot tub filter


  • Hot tub filters keep debris and bacteria from entering your water. When you soak in your hot tub, you might be unaware about just how much bacteria you could be surrounded with if you didn’t have a filter in place. A warm, wet environment is the perfect breeding ground for many kinds of bacteria, but filters can help you cut down on that exposure significantly. They can also catch sediments, minerals, dirt, and large debris before it reaches you.
  • Filters in your hot tub can keep air from entering your pipes. When air finds its way into the pipes and inner workings of your hot tub, it can cause a lot of damage, especially if it manages to reach your pump. Where a simple $20 filter cartridge replacement could have stopped you from having this problem at all, now you will find yourself faced with a much more expensive pump repair or replacement to deal with.
  • Hot tub filters can keep your jets from being damaged. If air or debris finds its way into your pipes, it can sometimes cause your jets to overload. If this happens, you’ll no longer have nice soothing bubbles to enjoy while you soak in your hot tub. Jets can be more difficult to replace than the filter cartridge as well, and if the pipes become too clogged, it may be a much bigger job than you ever thought to get them cleared out enough to work correctly again. Keep a filter in place at all times to prevent this from happening.

Hot Tub Filter Reviews

Below are fourteen of the best replacement hot tub filters on the market today. Depending on the type of hot tub you have, you might find the perfect new filter among these excellent products. Remember that, while many types of hot tub filters are interchangeable, the best way to tell which type you need to purchase for your specific spa is to check your owner’s manual. This can let you know the dimensions and specifications you need to keep in mind before you go shopping for your new filter.

1. Pleatco PWK30 Replacement Cartridge​

Pleatco PWK30 Replacement Cartridge for Watkins Hot Spring Spas, 1 Cartridge

The Pleatco PWK30 Replacement Cartridge is a great option for anyone looking to replace the filter cartridge in just about any standard spa filter. Made with a pleated filter media surrounding an open ABS plastic core, this filter is designed to allow water to move freely through it without being hampered by any of its working parts. Even the lid and base of this filter are designed to withstand extended use, and they are made to hold up to repeated exposure to chlorine and other frequently used hot tub chemical treatments.



  • An affordable solution that is universal to just about any hot tub with a cartridge style filter.
  • Tried and true design that is proven to remove bacteria and debris from the water.
  • Easy to rinse between the pleats with a garden hose when it’s time to clean.
  • Some more expensive brand name spas may not work with a universal cartridge replacement.
  • May not be able to stand up to frequent soaking in bleach or other harsh chemicals.
  • May not have a full year lifespan like other filter models available.

2. Unicel C-4950 Replacement Filter Cartridge

Unicel C-4950 Replacement Filter Cartridge for 50 Square Foot Rainbow, Waterway Plastics, Custom Molded Products

If you have a hot tub filter system that requires a larger filter, the Unicel C-4950 Replacement Filter Cartridge may be the right one for you. This cartridge is designed for use with a variety of different hot tubs and filters to make it easy for you to install it no matter what kind of spa system you have. Choose between a single replacement, a two pack, or even a ten pack to save a lot of money in the long run. This product is designed with a pleated filter media to help catch as much bacteria and debris as possible without ever letting it enter your hot tub.



  • Very affordable alternative to other, more expensive filters.
  • Available in a convenient ten-pack option to help you save a lot of money.
  • Works well with a variety of different hot tubs, including big name brands.
  • May not be as durable as other filters on the market.
  • Prone to falling apart when soaked in bleach or other harsh chemicals for too long.
  • Has been known to be difficult to install in some hot tub models.

3. Bestway Spa Filter Pump Replacement Cartridge Type VI

Unicel C-4950 Replacement Filter Cartridge for 50 Square Foot Rainbow, Waterway Plastics, Custom Molded Products

The Bestway Spa Filter Pump Replacement Cartridge Type VI is designed specifically for use with inflatable spas. However, this filter is more or less interchangeable with most varieties of inflatable spas, so even though you can’t use it in a traditional standalone hot tub, you can still find a use for it no matter what type of inflatable model you might have. You can purchase this filter in a pack of twelve to save a ton of money in the long run, or order as few as two at a time if you prefer to give it a test run first.



  • This is a small filter that fits well into the smaller filter compartments for inflatable spas.
  • These filters are very easy to clean with a simple garden hose and can be easily maneuvered for a deep clean.
  • This is an affordable option that can provide you with years of clean filters at a very low cost.
  • Cannot be used with a bleach or other harsh chemical soak, as these filters will fall apart after even one soak.
  • May cause a strange smell in the hot tub when used with chemical water treatments.
  • May need to be replaced more frequently than other types of filters listed here.

4. Pleatco PDO75-2000 Replacement Cartridge

Pleatco PDO75-2000 Replacement Cartridge for Dimension One 75, @Home Hot Tubs (Open with Twist Lock), 1 Cartridge

The Pleatco PDO75-2000 Replacement Cartridge is an excellent filter solution for those tough to clean hot tubs. This filter is designed with a 50% hollow center which makes it easier for water to flow throughout the filter and all of its pleats. This, in turn, allows for bacteria to catch quickly and easily on the filter media, which means you can enjoy cleaner water right away as soon as you install this filter into your spa. Best of all, the plastic lid and base are designed not to disintegrate with prolonged exposure to pool and spa chemicals.



  • Filter media material is designed to hold up to repeated use and cleaning, even when you use harsh chemicals.
  • Easy to swap out with larger filter cartridges from just about any of the models available on the market today.
  • Features plenty of pleats to help filter your water despite its larger size.
  • May be difficult to fit into some big name brand spa filter housing units.
  • Blue plastic has been known to chip off with extended use and may enter the hot tub water.
  • The design features no handles so removing the filter from the housing unit may be difficult.

5. Pleatco PRB35-IN Replacement Cartridge

Pleatco PRB35-IN Replacement Cartridge for Dynamic Series IV - DFM, DFML, Waterway 35, In-Line, 1 Cartridge

If you have the type of hot tub that requires a very finely pleated filter cartridge, look no further than the Pleatco PRB35-IN Replacement Cartridge. This filter cartridge is designed to work with many of the big name brands of hot tubs available on the market today, and it can easily be modified to fit into some other types of hot tubs as well. This filter is large enough to remove a good amount of bacteria and debris from the water and fine enough to keep from allowing anything to pass through aside from the crystal clean water itself.



  • This filter is durable enough to hold up to repeated soaking and cleaning as well as extended use.
  • This is a great filter solution if you have a hot tub with a difficult to find filter cartridge replacement, as it is a unique size.
  • This is an easy filter to install and remove by hand.
  • This filter may need to be replaced sooner than one year after use, depending on how often you use your hot tub.
  • The pleats in this filter may be harder to separate and clean with a garden hose than others listed here.
  • This filter may be slightly more costly than some of the others on the market, as you cannot purchase it in a multiple filter pack.

6. Filbur FC-0359 Antimicrobial Replacement Filter Cartridge

Filbur FC-0359 Antimicrobial Replacement Filter Cartridge for Select Pool and Spa Filter

Are you looking for an excellent universal filter cartridge for a wide variety of different hot tubs and pools alike? Try the Filbur FC-0359 Antimicrobial Replacement Filter Cartridge to satisfy all your filtering needs! This is a great filter that can be used throughout the world of pools and spas. It features a reinforced pleated filter media that won’t pop out with extended use, and it’s designed to stand up to being washed and reused time and time again. If you have a standard hot tub, chances are good this filter is just waiting for you.



  • Durable and strong, and designed with a barrel that is resistant to breaks and damage.
  • Features a handy grip on the lid of the cartridge to make it easy to install and remove.
  • Strong enough to soak in any type of chemical cleaner you choose to use on your filter.
  • May not fit every type of spa on the market today, particularly older models.
  • Pleated media is difficult to separate enough to rinse out well with a garden hose.
  • May require more than one soak to completely clean this filter each time.

7. FilburFC-2390 Antimicrobial Replacement Filter Cartridge

50 sq. ft. Pool Filter Replaces Unicel C-4950, C-4950-2, Pleatco PRB50-IN, Filbur FC-2390-Pool and Spa Filter Cartridges

Are you searching for the perfect durable filter cartridge replacement for your hot tub? If so, choose the Filbur FC-2390 Antimicrobial Replacement Filter Cartridge to take care of your needs. This cartridge is designed to replace filters in the Pentair and Rainbow spa filter systems. Although it cannot be used interchangeably with all filters across the board, it still provides an excellent affordable alternative to purchasing name brand filters every time you need to make a change.



  • This filter features a reinforced design that won’t break, chip, or bend with extended use.
  • The filter media material is designed to stand up to cleaning again and again, so you can use this filter and reuse it.
  • This filter provides a very affordable alternative to many other comparable filters on the market today.
  • Does not come with all of the necessary parts, so you may need to retain attachment pieces from your previous filter cartridge.
  • Because of the fine pleating in this filter, some debris may backwash into the spa tub.
  • May be too small to work with some older models of Rainbow or Pentair filters.

8. Filbur FC-2401 Antimicrobial Replacement Cartridge

Filbur FC-2401 Antimicrobial Replacement Filter Cartridge for Freeflow Legend Pool and Spa Filter

The Filbur FC-2401 Antimicrobial Replacement Cartridge is designed specifically for use with the Freeflow Legend spa, but it is capable of being used with a variety of others with a similar setup as well. This filter is designed with molded media threading to ensure that the pleated polyester never pops loose of the rest of the filter cartridge. It’s made for repeated use, so simply remove it from it from your filter system, clean it, and replace it for up to a year without having to buy a new cartridge.



  • Features a reinforced design that keeps the filter cartridge from breaking or bending even under pressure or extended use.
  • Comes equipped with an easy to use grip that makes installation and removal a snap.
  • Features a durable top and bottom piece that can hold up to a lot of exposure to cleaning and treatment chemicals in and around your hot tub.
  • May be difficult to clean, as the pleating in this filter catches a great deal more grime and debris than many others.
  • May be more expensive than other comparable filters on the market today.
  • If the pleats are not rinsed well, debris may backwash into the spa tub with extended use.

9. Happy Hot Tub 3x Tri-X Filters

Happy Hot Tub 3 x Tri-X Filters Hotspring Hot Spring PWK30 Replacement Cartridge

Do you have the type of hot tub that requires wider pleats in its filter cartridge media? Is your hot tub difficult to find a match for when it comes to replacement filters? If so, give the Happy Hot Tub 3x Tri-X Filters a try. This set of three large, durable hot tub filters is designed for use in the Hot Spring model of hot tubs, but it may be used in a variety of other models as well. These unique filters are made from ceramic rather than from traditional polyester or paper like other types of pleated filters. The ceramic is molded to give the appearance and design of pleats with none of the flimsiness that comes from paper filters. Choose these filters if you want something that is sure to last you for a long time to come.



  • Pleated ceramic filters are made for easy cleaning and even easier use over time without damage to the filter components.
  • Can be washed in the dishwasher with just a little bit of normal dish detergent when it comes time to clean these filters.
  • Despite being larger and heavier than traditional cartridges, these are easy to install and remove with just a few quick motions.
  • These filters are mostly designed to replace Watkins brand filters and may not be able to be used with every type of hot tub.
  • These are very expensive filters that come in at well over the price range of the polyester and paper filters listed here.
  • If you try to use these filters with an incompatible hot tub, the spa likely will not function at all.

10. Pleatco PFF50P Replacement Cartridge

Pleatco PFF50P Replacement Cartridge for Freeflow Spas Legend, 1 Cartridge

Choose the Pleatco PFF50P Replacement Cartridge for a durable, finely pleated cartridge that is built to last. This replacement filter cartridge is made to work with the Freeflow Spas Legend model hot tub, but it is interchangeable with quite a few others on the market today. The center of this cartridge is made from durable but hollow ABS plastic that can handle a lot of use and water flow without breaking while still allowing for the water to filter through appropriately. The pleats in this cartridge are antimicrobial, which makes your water cleaner than ever before by the time it reaches the tub portion of your spa.



  • This durable filter is easy to install and remove with just a few simple twists when it’s time to change the filter.
  • This filter can easily be cleaned by simply parting the pleats and rinsing with a garden hose in between soaking.
  • Comes packaged with fittings needed to adjust the filter cartridge to most compatible hot tub filter systems.
  • The filter may be too tall to fit into some hot tub filter housing units, even when the other dimensions are correct.
  • The threading holding the filter media in place may become loose over time, especially with frequent cleaning.
  • Might be a bit more expensive than other comparable filters on the market today.

11. Pleatco PWW50P3-M Replacement Cartridge

The Pleatco PWW50P3-M Replacement Cartridge filter is designed for use with Aber brand hot tubs. However, it can be used with many other models as well, provided your filter system has the appropriate dimensions. This cartridge is unique in that it is also designed for use with water skimmers, so you can have even cleaner water when you utilize this cartridge to its fullest potential. The end caps are antimicrobial and keep the rest of the cartridge from becoming too damaged or weakened by frequent exposure to chemicals and hot water in your spa. Best of all, this filter is made to resist the buildup of algae and bacteria that causes damage and bad smells in your hot tub.



  • This durable filter is made to last for a long time and likely will not need to be fully replaced for up to one year.
  • This is a very affordable filter that comes in at a much lower price than many others made for the same models of hot tubs.
  • Easy to use in both pools and spas, making it a great choice for anyone who has one of each.
  • Has been known to sit slightly crookedly or off-center in the filter housing unit.
  • May not be able to stand up to soaking in harsh chemicals for very long at all.
  • Blue color may sometimes bleed into hot tub water.

12. Unicel 6CH-940 Waterway Replacement Cartridge

New Unicel 6CH-940 Waterway Vita Aber Spa Filter Replacement Cartridge 6CH940

The Unicel 5CH-940 Waterway Replacement Cartridge is made to be used with Aber brand spas, but it is interchangeable with a few other brands as well. This durable filter features reinforced fine pleats that are meant to capture as much bacteria, dirt and debris as possible before it ever reaches your hot tub. The filter media is made of polyester, which means it is strong enough to be used a few times before it will need to be replaced. This is a powerful filter that can hold up to soaking in harsh chemicals for a short period of time when you need to do a deep and thorough cleaning.



  • This is a very affordable filter that is sure to save you plenty of money in the long run.
  • Features an easy to maneuver grip for quick and simple installation and replacement.
  • Sturdy threading and design keep this filter from falling apart even after repeated use and cleaning.
  • The filter media may be too coarse to function properly on some models of hot tubs.
  • Pieces of the plastic casing have been known to chip or break off and float into the hot tub water.
  • This filter is not as interchangeable with other models as some of the others listed here.

13. 2-Pack Clarathon Spa Filter Replacement

2-Pack Clarathon Spa Filter Replacement for Sundance Microclean 6540-502 FC-2812

Use the 2-Pack Clarathon Spa Filter Replacement in conjunction with a traditional pleated cartridge filter for the cleanest hot tub water you can possibly imagine! This microfilter is meant to sit on top of your traditional filter cartridge to give your water a second, more thorough cleaning every time it passes through the filter system. Bear in mind that not all hot tubs are compatible with a microfilter and your instruction manual should let you know if yours is. If so, do yourself a favor and pick up a pack of these microfilters right away. You’ll be surprised at just how clean and comfortable your water can really be when you use them!



  • Works just as well as, if not better than, better-known brand name microfilter replacement cartridges.
  • Much more affordable than the brand name microfilters made by some of the best-known companies.
  • Easy to use along with your cartridge filter as long as your hot tub is compatible.
  • Must be used along with a traditional cartridge filter and cannot be used on its own.
  • May need to be replaced much more frequently than the cartridge filter, as this filter is much smaller and may get blocked more easily.
  • Can be difficult to clean and may not have a lot of repeat value per filter.

14. 2 Replacement Filters for Lifesmart

2 Replacement Filters for Lifesmart, Freeflow, AquaTerra, Hydromaster, Grandmaster, Simplicty, Bermuda Spas - 50SF [2-PACK]

These 2 Replacement Filters for Lifesmart are meant to be used with Lifesmart hot tubs, but they are also compatible with Grandmaster, Hydromaster, Simplicity, and a wide variety of other, similar hot tub brands. This is a very traditional size and shape of hot tub filter, so chances are good you will be able to make the most of it in your spa. The filter media is finely pleated, which means it is able to catch even the smallest of sediment, minerals, and other debris that you don’t want to enter your hot tub water. Use this filter and you’ll be pleased with just how long it is sure to last.



  • This filter features an easy to grip handle that makes removing and replacing it a snap.
  • The filter is designed to work with many of the biggest sellers in the world of hot tubs.
  • This filter’s pleated media is strong enough to be cleaned with harsher cleaning solutions as long as you don’t over-soak it.
  • This is a lesser-known brand name, so if you’re looking for something with a lot of customer satisfaction and years of experience to back up the product, you might want to look elsewhere.
  • The pleated media in this filter cartridge is tied together with a string pull and not reinforced and threaded, meaning it may pop loose sometimes.
  • The lid and base to this filter are not designed for extended exposure to chemicals in your hot tub.


There are a lot of options available to you when you buy your filter replacements on Amazon! Keep in mind the following tips and tricks to make your online shopping go much more smoothly:

  • Always check the reviews. Even if a product is brand new, if it has only a handful of reviews you’ll be able to tell if it’s worth your money or not.
  • Check how many of a certain product has been sold. Every consumer doesn’t necessarily leave a review, so pay attention to the number of a product that has been sold in order to tell how popular it is.
  • Remember that you do have return options if you’re buying from Amazon. If your product doesn’t arrive as described, you can always send it back.
  • Only choose filters that list their product specifications in an easy to find location on the listing. This will ensure that you get a good product with a quality guarantee every time.
  • Try to buy from sellers with a customer service option listed on their profile page. This will allow you to get in touch if a problem arises with your order.
  • Always measure your previous filter cartridge or check the dimensions recommended in your filter’s instruction manual. This way, you can be sure to get a filter size that works for your hot tub.
  • Check your previous filter for any significant installation issues, such as a unique type of screw or o-ring, that might not come with a replacement filter. Be sure to keep any of these on hand if you think you might need them to install the next filter.

When you keep these tips in mind, you’ll have no trouble ordering your replacement filters through Amazon and getting the perfect product every time.