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1-Pack Excel Filters XLS-938 replacement filter cartridge for Waterco Opal XL 180/XL 270 lower element
1-Pack Excel Filters XLS-938 replacement filter cartridge for Waterco Opal XL 180/XL 270 lower element — view 2
1-Pack Excel Filters XLS-938 replacement filter cartridge for Waterco Opal XL 180/XL 270 lower element — view 3
1-Pack Excel Filters XLS-938 replacement filter cartridge for Waterco Opal XL 180/XL 270 lower element — view 4
Cutaway diagram of an Excel Filters cartridge labelling its Cleanguard ultra-efficient media, optimal-flow engineered core, secure fit banding and durable end caps
Six-step illustrated guide to cleaning a pool filter cartridge: switch off the pump and release pressure, remove the cartridge, rinse it with a garden hose, flip it over and repeat, refit it in the housing, then enjoy the pool
A child floating with a kickboard in a clean swimming pool, above the line "Excel Filters replacement cartridges clean your pool and spa"
A golden retriever swimming underwater in a clear blue pool, above the line "Cleaner, clearer water. That’s how we Excel."
1-Pack 01 / 08
Waterco CompatiblePool Filter

Excel Filters XLS-938 Replacement Filter Cartridge for Waterco Opal XL 180 / XL 270 Lower Element — 1-Pack

Compatible Replacement for Waterco 701038. Cross-References Unicel C-9444.

Made in the USA by Excel Filters

SKU XLS-938 1PACK · UPC 810625020648

$109.99 Single Cartridge
Free shipping. Tax calculated at checkout.
In stock 61 cartridges ready to ship from Austin

30-day returns.

  • Perfect Fit Guarantee*On listed part numbers
  • Free Standard Shipping*Every order, no minimum.
  • 6-Month Warranty*Covers manufacturing defects

Confirm your fit

  • Your housing — Waterco Opal XL 180, Waterco Opal XL 270 lower/long-element position (used with one XLS-937).
  • Your old part number — 701038, C-9444. See all 4 compatible parts →
  • Your measurement — 10 3/10" diameter, 17 1/4" height, 3" Open End caps top and bottom.

Overview

Built to OEM Spec, Engineered to Clean®

Built to OEM dimensions for Waterco Opal XL 270, Opal XL 180, and 270. WaterCo Part Number 701038 cartridge filter systems, this replacement matches the original cartridge geometry, end-cap style, and media surface area — without the OEM markup. It directly replaces OEM Waterco® 701038 and aftermarket Unicel C-9444 part numbers — the full cross-reference list is in the Compatibility tab. Every cartridge is manufactured in our Austin, TX facility, ships free, and is backed by the Excel Filters Perfect Fit Guarantee on its listed cross-references.

The XLS-938 replacement cartridge is engineered for Waterco and built for dependable day-to-day filtration performance. Each cartridge is sized at 10 3/10" diameter x 17 1/4" length, with Open End top and Open End bottom end caps for direct-fit installation with no housing modifications.

Specifications

Measure once. Order with confidence.

Measure your old cartridge cap to cap, then across the widest pleat.

How to measure a cartridge →
Outer diameter
10 3/10"
Overall length
17 1/4"
Top end cap
3" Open End
Bottom end cap
3" Open End
Media per cartridge
184 ft²
Total media
184 ft²

Measuring your old cartridge

  • Length — cap to cap, with both end caps included.
  • Diameter — across the widest point of the pleats, not the end cap.
  • End caps — whether each end is open or closed, and the size of any opening.

A variance of ⅛" is normal. Anything larger usually means a different housing model — check the number printed on your old cartridge against the compatible parts list before ordering.

Cross-reference

Check compatibility by system or part number

Match your filter housing below, click any part number to verify the fit, or paste your existing part number into the search box.

Fits These Systems

Filter housings and systems this cartridge fits

Waterco® Housings
Waterco Opal XL 180Waterco Opal XL 270 lower/long-element position (used with one XLS-937)

Replaces These Part Numbers

OEM and competitor cartridge part numbers this product replaces

Waterco®
Unicel
Fit note Qty per housing: 1; Opal XL 270 also needs 1 XLS-937.

The Perfect Fit Guarantee applies to the cross-references listed here. Brand names, models and part numbers identify compatibility only. If your housing is not listed, reach out to our team before ordering.

Can't find your part number? Look it up on the full pool filter cartridge cross-reference chart.

Reviews

What pool pros and homeowners are saying

Need help fitting?

Not sure if this fits your housing?

Enter your current cartridge's part number, your housing model, or a competitor number — we'll check it against this filter and the full catalog.

Questions

Fit, replacement & ordering

Still unsure after reading these? Send us the number stamped on your old cartridge and we will confirm the fit.

What part numbers does the XLS-938 replace?

The Excel Filters XLS-938 replaces Waterco 701038, and aftermarket equivalents Unicel C-9444.

Which filter systems does the XLS-938 fit?

It fits Waterco Opal XL 180, Waterco Opal XL 270 lower, long-element position (used with one XLS-937). If your housing is not listed, match the part number stamped on your current cartridge on our cross-reference chart.

What are the dimensions of the XLS-938 cartridge?

10 3/10" diameter, 17 1/4" long, 180 ft² of media (end caps — top: 3" Open End, bottom: 3" Open End). Measure your old cartridge before ordering if you are unsure of the part number.

Is this a genuine Waterco part?

No. The XLS-938 is an independently manufactured replacement cartridge, made in the USA by Excel Filters and built to match the Waterco 701038 specification. Waterco is a trademark of its owner, used only to show compatibility.

How often should the XLS-938 be replaced?

Most pool and spa cartridges last 1–2 seasons with regular rinsing. Replace it when cleaning no longer restores flow, the pleats fray, or the end caps crack.

Other sizes in this family

If your housing is a different model

All Waterco Opal XL Replacement Filter Cartridges →
Back to all filters

*Perfect Fit Guarantee applies to the OEM and aftermarket cross-references listed on this page; brand names, models and part numbers identify compatibility only. We ship to the 48 contiguous United States only; free standard shipping applies to those orders with no order minimum, and expedited service is priced at checkout. Every cartridge carries a 6-month limited warranty against defects in materials and manufacturing, separate from our 30-day return policy.