PLAS35 / 5CH-203 / FC-0303
35 sq ft replacement filter cartridge • 5.375″ OD × 8.5625″ 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 | PLAS35 | Primary |
| Unicel | 5CH-203 | Equivalent |
| Filbur | FC-0303 | Equivalent |
| OEM | LA Spas HTF-303 | Original Equipment |
| OEM | LA Spas FD-51500 | Original Equipment |
Always verify dimensions and end-cap type before purchasing a replacement.
Compatible Hot Tubs & Spas
The following spa models use the PLAS35 (or an interchangeable equivalent). Always confirm with your owner's manual.
| Brand | Model |
|---|---|
| LA Spas | Various |
| American Whirlpool | Models 250-282 |
Frequently Asked Questions
What are the dimensions of the PLAS35?
The PLAS35 measures 5.375 inches in outer diameter and 8.5625 inches in length, with a handle top and open bottom. It provides 35 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 PLAS35?
The PLAS35 is interchangeable with 5CH-203, FC-0303, and OEM equivalents including LA Spas HTF-303, LA Spas FD-51500. All of these share the same 5.375" OD × 8.5625" dimensions and handle 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 PLAS35 filter cartridge?
The PLAS35 (35 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 PLAS35 filter cartridge?
The PLAS35 has a handle on top, making it easier to lift out of the housing without touching the filter media. 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 PLAS35 filter?
The PLAS35 is compatible with the following models: LA Spas Various, American Whirlpool Models 250-282. 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 | 5.375″ |
|---|---|
| Length | 8.5625″ |
| Top Type | Handle |
| Bottom Type | Open (no end cap) |
| Filtration Area | 35 sq ft |
| Primary Brand | Pleatco |
| Part Number | PLAS35 |