A hot tub pre-filter sits ahead of the main filter to catch oils, soap, hair, and other suspended particles before they reach the main cartridge. The right choice depends first on fit: many of the options below are made for specific skimmer baskets and spa systems, while one is a main filter cartridge rather than a pre-filter. Check your spa’s manual, part number, and basket dimensions before ordering.
Table of Contents
Quick Comparison
| Product | Pack Size | Key Fit or Feature | Best For |
|---|---|---|---|
| SlogPith Hot Tub Pre Filter | 6 filters | MAAX First Filter-compatible systems; listed as 10-micron | A multipack with a stated filtration rating |
| Femitu 100497 First Filters | 4 filters | Listed diameter: 7 3/4 inches; several named spa systems | Shoppers who want a stated size and part number |
| HANXER 6540-502 Filter Cartridge | 1 cartridge | Main cartridge replacement, not a pre-filter | Owners seeking a compatible main filter cartridge |
| DuckcowsC 100497 First Filters | 6 filters | 100497 replacement for several listed spa systems | A larger pack of 100497-style filters |
| Alocs First Filter | 4 filters | MAAX, American Whirlpool, and Coleman systems; listed as 10-micron | Shoppers seeking a stated filtration rating and tab fit |
Our Picks: Best Pre Filter For Hot Tub reviews
1. SlogPith Hot Tub Pre Filter: Best Overall Multipack
The SlogPith is a six-pack of pre-filters designed to sit on top of a skimmer basket. Its listed compatibility includes systems that use a MAAX First Filter, along with American Whirlpool, Coleman, and LA Spas models. It is a third-party accessory, so check your basket size and fit before buying rather than relying on the brand list alone.
The product description lists polypropylene construction and 10-micron filtration. It is intended to catch oils, lotions, and debris before they reach the main filter. Rinsing it weekly is the suggested maintenance routine, with replacement every two to three months depending on use.
The six-filter pack may suit owners who want several replacements on hand. Its main limitation is the need to confirm compatibility: spa brand names can cover different basket designs, and this product specifically advises checking basket size. It also should not be treated as a substitute for your spa’s main filter cartridge.
Pros:
- Six filters in one pack
- Lists 10-micron filtration
- Designed for placement on top of the skimmer basket
- Names several compatible spa-system families
Cons:
- Basket size and fit need to be verified
- Third-party accessory, not an OEM filter
Verdict: Choose the SlogPith if your basket matches its fit requirements and you want a six-pack with a stated filtration rating.
2. Femitu 100497 First Filters: Best for a Stated Basket Diameter
Femitu’s four-pack is a 100497-style first filter intended to fit on top of the skimmer basket. The product description lists MAAX, American Whirlpool, Coleman, LA Spas, California Cooperage models from 1998–2009, and Elite Spas among the compatible systems. It also gives a 7 3/4-inch diameter, which can help you compare the product with your existing filter.
The filter is described as having a chemical-fiber filtering layer and a polypropylene frame. Its role is to capture soap, oil, and suspended particles before they reach the main cartridge. The instructions call for weekly rinsing and replacement about every three months, with more frequent rinsing if use or visible buildup calls for it.
The stated diameter and 100497 part number make this a useful option when you are matching an existing filter. However, a matching diameter by itself does not guarantee that the notches or basket shape will line up. Check the part number and installation details for your spa before ordering.
Pros:
- Includes four first filters
- Lists a 7 3/4-inch diameter
- Identifies the 100497 filter type and several compatible systems
- Designed for straightforward placement on the skimmer basket
Cons:
- Notch alignment and basket fit still need checking
- Does not state a micron rating in the supplied product details
Verdict: The Femitu is a practical choice when your spa uses a 100497-style filter and its basket dimensions and notches match.
3. HANXER 6540-502 Cartridge: A Main Filter, Not a Pre-Filter
The HANXER is a replacement filter cartridge, not a pre-filter that sits on a skimmer basket. The listed compatible models include 6540-502, Filbur FC-2812, Sundance Series 850 and 780, and PPS750. Its stated dimensions are 5 inches long, 7 3/4 inches in outside diameter, with open top and bottom openings measuring 4 7/8 inches.
The product description says its woven polymer material is designed to filter sediment, hair, and other particles. It is described as suitable for pools and spas. The listing also identifies it as a disposable filter and says not to use filter cleaner on it.
This product belongs in the comparison because it is a hot tub filter, but it does not perform the same job as the pre-filters above. If you need a layer that sits over a skimmer basket to catch oils and soap before they reach the main cartridge, this is the wrong type. It may be relevant if you are instead replacing a main cartridge and the model and dimensions match.
Pros:
- Lists several compatible cartridge model numbers
- Provides key dimensions for fit comparison
- Designed to filter sediment, hair, and other particles
Cons:
- Not a hot tub pre-filter
- Disposable and not intended for use with filter cleaner
Verdict: Consider the HANXER only if you need a compatible main filter cartridge; choose a basket-style first filter for pre-filtration.
4. DuckcowsC 100497 First Filters: Best Six-Pack for Compatible Spas
This six-pack is listed as a replacement for part number 100497. Its stated compatibility includes MAAX, American Whirlpool, Coleman, LA Spas, California Cooperage models from 1998–2009, and Elite spas. The pre-filters are made with polypropylene and chemical fiber, and are designed to sit in the skimmer basket.
The product description says the filter is intended to catch soap, dirt, hair, body oils, and other suspended particles before they enter the main filter. Having six replacements on hand can make it easier to follow a regular replacement routine without ordering as often. The listing does not provide a diameter or micron rating, so compare the shape and part number with your existing filter before purchasing.
Like other first filters, it is an added filtration layer rather than a replacement for the spa’s main cartridge. The six-pack is the main distinction compared with the four-filter Femitu and Alocs packs, while the Femitu listing provides a specific diameter and the Alocs listing states a micron rating.
Pros:
- Six filters in the pack
- Lists 100497 as the replacement part number
- Names several compatible spa brands and systems
- Designed to catch oils, hair, and other suspended particles before the main filter
Cons:
- No diameter or micron rating is given in the supplied details
- Compatibility should be checked against your specific basket and part number
Verdict: The DuckcowsC is worth considering if you need a 100497-style first filter, want a six-pack, and have confirmed the fit.
5. Alocs First Filter: Best Four-Pack with a Stated Micron Rating
The Alocs four-pack is designed for MAAX, American Whirlpool, and Coleman spa systems. The product is described as a 10-micron polypropylene filter that sits on top of the skimmer basket, with tabs that lock into existing MAAX basket slots. That tab detail makes it especially important to check your basket design before ordering.
Its stated purpose is to catch soaps, oils, lotions, and other suspended particles before they reach the main cartridge. The product description recommends weekly rinsing and replacement about every three months, depending on spa use. Rinsing can remove visible debris between replacements, but this filter is still a pre-filter rather than a substitute for the main cartridge.
Compared with the SlogPith, the Alocs also lists a 10-micron rating but comes in a four-pack and describes a tab-lock installation. Compared with the 100497 options, it is more specific about the installation tabs and filtration rating. Confirm your model and basket slots before choosing it.
Pros:
- Lists 10-micron polypropylene filtration
- Describes tab placement for compatible MAAX skimmer baskets
- Four filters included
- Provides a rinse and replacement routine
Cons:
- Compatibility list is narrower than some other options
- Tab and basket fit must match your spa
Verdict: Choose the Alocs if your spa is compatible with its tab design and you want a four-pack with a stated 10-micron rating.
How to Choose a Pre-Filter for Your Hot Tub
Confirm the Filter Type You Need
A pre-filter, sometimes called a first filter, sits on or in the skimmer basket ahead of the main filter cartridge. It is meant to catch some oils, soap, hair, and other suspended particles before they reach the main filter. A cartridge like the HANXER is a different product: it replaces a main filter rather than adding a basket-level pre-filter. Check your spa manual or existing part number to confirm which type you need.
Match the Part Number and Spa Model
Use the spa model, existing filter part number, and manufacturer guidance as your first checks. Product listings may name several spa brands, but systems from the same brand can use different baskets or filter designs. Part numbers such as 100497 can help narrow the choice, but they should still be checked against your spa’s specifications.
Check the Basket Size and Attachment Style
Compare the filter’s stated diameter with your basket and look for tabs, notches, or other attachment details. The Femitu listing gives a 7 3/4-inch diameter, while the Alocs listing describes tabs that lock into existing MAAX basket slots. Other listings also advise checking basket fit. A filter that is close in size but does not sit securely may not be the right match.
Understand What the Filtration Claims Mean
Some products list a micron rating, such as the 10-micron rating stated for SlogPith and Alocs. Other listings focus on the material or the types of particles the filter is intended to catch. Use these details to compare products, but do not assume a stated rating makes a filter compatible with your spa. Fit and filter type come first.
Consider Pack Size and Replacement Needs
These options come in packs of four or six, which can give you replacements on hand. The descriptions generally suggest rinsing pre-filters weekly and replacing them after a period of use, with the exact routine depending on the product and spa use. Follow the instructions for the specific filter you buy, and replace it when needed rather than relying on pack size alone.
Keep the Main Filter in Your Maintenance Plan
A pre-filter adds a layer of filtration; it does not remove the need to maintain or replace your main filter. Follow your spa and filter manufacturers’ instructions for the main cartridge. If you are shopping for a replacement cartridge rather than a basket insert, make sure the model number, dimensions, and opening style match.
Frequently Asked Questions
What does a hot tub pre-filter do?
A pre-filter sits ahead of the main filter and is designed to catch particles such as oils, soap, hair, and debris before they reach the main cartridge. The exact materials and filtration details vary by product.
Is a pre-filter the same as a hot tub filter cartridge?
No. A pre-filter is fitted at the skimmer basket as an additional filtration layer. A cartridge is typically the main filter element. The HANXER product in this list is a cartridge replacement, not a basket-style pre-filter.
How do I know whether a pre-filter will fit my spa?
Check the spa manual, the part number on your current filter, and the dimensions and attachment style of your skimmer basket. If a listing names your spa brand but does not specify your exact model, verify the fit before ordering.
How often should I rinse a hot tub pre-filter?
The product descriptions here generally recommend rinsing weekly. They also suggest rinsing more often when the filter has visible buildup or the spa is used more heavily. Follow the instructions for your specific product.
How often should I replace a pre-filter?
Replacement guidance varies. Some listings suggest changing the filter about every three months, while SlogPith gives a range of two to three months depending on use. Follow the product directions and replace it as needed.
Can a pre-filter reduce the need to clean or replace the main filter?
These products are designed to catch some particles before they reach the main filter and may help reduce its workload. They do not eliminate the need to clean or replace the main cartridge according to your spa’s maintenance instructions.
Which option should I choose if I want a six-pack?
SlogPith and DuckcowsC both come in six-packs. SlogPith lists a 10-micron rating and advises checking basket size; DuckcowsC is listed as a 100497 replacement but does not provide a diameter or micron rating in the supplied details. Compare the fit requirements with your spa before choosing.
Final Recommendation
For a general-purpose pick, the SlogPith offers a six-pack and a stated 10-micron rating, provided its basket fit matches your spa. Choose the Femitu or DuckcowsC if you have confirmed that your system uses a compatible 100497-style first filter, or consider Alocs if its tab design matches your basket. The HANXER is only a choice for replacing a compatible main cartridge, not for adding a pre-filter. In every case, verify the filter type, part number, and fit before ordering.
