PWK30 / C-6430 / FC-3915
30 sq ft replacement filter cartridge • 5.875″ OD × 10.5″ long
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Use the part-number links below to compare compatible cartridges. Prices and availability vary, so verify dimensions before ordering.
Cross-Reference & Interchangeable Part Numbers
| Brand | Part Number | Type |
|---|---|---|
| Pleatco | PWK30 | Primary |
| Unicel | C-6430 | Equivalent |
| Filbur | FC-3915 | Equivalent |
| OEM | Watkins 31489 | Original Equipment |
| OEM | Hot Spring 31489 | Original Equipment |
Always verify dimensions and end-cap type before purchasing a replacement.
Compatible Hot Tubs & Spas
The following spa models use the PWK30 (or an interchangeable equivalent). Always confirm with your owner's manual.
| Brand | Model |
|---|---|
| Hot Spring | Jetsetter |
| Hot Spring | Prodigy |
| Hot Spring | Sovereign |
| Hot Spring | Grandee |
| Hot Spring | Vanguard |
| Hot Spring | Envoy |
| Hot Spring | Hot Spot Tempo |
| Hot Spring | Hot Spot Relay |
| Hot Spring | Hot Spot Rhythm |
| Hot Spring | Solana |
Frequently Asked Questions
What are the dimensions of the PWK30?
The PWK30 measures 5.875 inches in outer diameter and 10.5 inches in length, with a open top and open bottom. It provides 30 square feet of filtration area. Always measure your existing cartridge or check the label inside the filter housing before ordering - outer diameter and length are the two critical dimensions, but end-cap style must also match.
What other part numbers are interchangeable with the PWK30?
The PWK30 is interchangeable with C-6430, FC-3915, and OEM equivalents including Watkins 31489, Hot Spring 31489. All of these share the same 5.875" OD × 10.5" dimensions and open top / open bottom end caps. When buying a cross-reference, confirm the end-cap style matches - a small difference in cap design can prevent proper seating in your filter housing.
How often should I replace a PWK30 filter cartridge?
The PWK30 (30 sq ft) is a mid-size spa filter. Plan on 12-24 months between replacements depending on how heavily the spa is used. Spas used daily or by multiple people will wear out filters faster than a spa used once or twice a week. A good rule of thumb: inspect it at every water change (every 3-4 months) and replace it when the pleats show tearing, channeling, or persistent discoloration.
How do I clean a PWK30 filter cartridge?
The PWK30 has open ends on both top and bottom, so water flows through freely. Remove the cartridge from its housing and rinse thoroughly with a garden hose, directing the stream at a 45-degree angle between the pleats - work from top to bottom, rotating around the cartridge. Avoid pressure washers, which collapse the pleats and permanently reduce filtration efficiency. For a deeper clean every 3-4 months, soak overnight in a hot tub filter cleaner solution, then rinse thoroughly. Never reinstall a wet cartridge if you're using a cartridge with a closed end - let it dry to prevent trapping moisture inside.
Which hot tubs and spas use the PWK30 filter?
The PWK30 is compatible with the following models: Hot Spring Jetsetter, Hot Spring Prodigy, Hot Spring Sovereign, Hot Spring Grandee, Hot Spring Vanguard, Hot Spring Envoy, Hot Spring Hot Spot Tempo, Hot Spring Hot Spot Relay, Hot Spring Hot Spot Rhythm, Hot Spring Solana. Always cross-check your spa's owner manual or the label inside the filter compartment to confirm the correct part number.
Dimensions
Specifications
| Outer Diameter | 5.875″ |
|---|---|
| Length | 10.5″ |
| Top Type | Open (no end cap) |
| Bottom Type | Open (no end cap) |
| Filtration Area | 30 sq ft |
| Primary Brand | Pleatco |
| Part Number | PWK30 |