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FilterHound

PD90SL / C-7409

90 sq ft replacement filter cartridge • 7″ OD × 26.25″ long

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Use the part-number links below to compare compatible cartridges. Prices and availability vary, so verify dimensions before ordering.

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Cross-Reference & Interchangeable Part Numbers

BrandPart NumberType
PleatcoPD90SLPrimary
UnicelC-7409Equivalent
OEMDoughboy 2396-090Original Equipment

Always verify dimensions and end-cap type before purchasing a replacement.

Compatible Pool Filter Systems

BrandModel
Doughboy90 sq ft Pool Filter

Frequently Asked Questions

What are the dimensions of the PD90SL?

The PD90SL measures 7 inches in outer diameter and 26.25 inches in length, with a closed top and open bottom. It provides 90 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 PD90SL?

The PD90SL is interchangeable with C-7409, and OEM equivalents including Doughboy 2396-090. All of these share the same 7" OD × 26.25" dimensions and closed 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 PD90SL filter cartridge?

The PD90SL (90 sq ft) is sized for smaller pool filter systems. Plan to inspect it every 3 months and replace it every 12-18 months. Heavy debris loads, high bather traffic, or imbalanced pool chemistry will shorten that timeline - if your filter pressure rises more than 8-10 psi above the clean starting pressure, it's time to clean or replace.

How do I clean a PD90SL filter cartridge?

The PD90SL has a closed (solid) top end cap. 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, soak the cartridge in a dedicated pool filter cleaner solution (following the product's dwell time instructions), then rinse completely before reinstalling. Having a spare cartridge on hand lets you swap and soak while the pool stays running.

Which hot tubs and spas use the PD90SL filter?

Refer to your spa's owner manual or the label inside the filter compartment to confirm compatibility. The part number is usually printed on the end cap of the existing cartridge.

Dimensions

7″ OD26.25″ L90 sq ftclosed top

Specifications

Outer Diameter7″
Length26.25″
Top TypeClosed (solid end cap)
Bottom TypeOpen (no end cap)
Filtration Area90 sq ft
Primary BrandPleatco
Part NumberPD90SL