PA106-PAK4 Pool Filter Replacement for Hayward C4030,C4020,C

The Verdict

Let’s cut to the chase: pool filter cartridges are the least glamorous purchase you’ll make all summer, but the wrong one means green water, a strained pump, and a wallet that’s suddenly lighter. The PA106-PAK4 replacement for Hayward C4030/C4020/C4025 filters has quietly built a 4.6-star reputation across 229 ratings, and after digging into what buyers actually say, here’s the real story.

What’s in the box

You get one filter cartridge. That’s it. No gaskets, no O-rings, no instruction booklet — just the filter itself, wrapped in plastic inside a thin cardboard box. The cartridge measures out to the same 7.75-inch diameter and 23.5-inch height as the OEM Hayward C-4025 replacement, with the same 36 square feet of filtering area. The pleats are densely packed and the end caps are rigid ABS plastic, not the flimsy stuff you see on bargain-bin filters.

Real-world performance

The most common thread in buyer feedback is the fit. Multiple reviewers note it slides into Hayward housings without forcing, and the center hole aligns perfectly with the standpipe. One verified buyer put it plainly: “This fit my C4030 exactly like the original. No gaps around the edges, no water bypassing the pleats.”

Filtering performance holds up too. The polyester fabric catches everything from algae debris to fine sand, and several reviewers report crystal-clear water within a day of installation. On the durability front, the reinforced pleats resist collapsing even when the filter runs dirty longer than it should. A few long-term reviewers mention getting a full season — and sometimes two — before needing replacement, which tracks with the 4.6 average rating.

Where it falls short

Honest downsides exist. The lack of a gasket is the most common complaint — you’ll need to reuse the one from your old cartridge or buy a $5 replacement. The slightly stiffer pleats also make initial insertion a bit snug; it’s not a dealbreaker, but you’ll want to be deliberate when seating it in the housing. And the minimal packaging means the cartridge can arrive with bent pleats if the box gets crushed in transit. Inspect it immediately.

Who should buy this

Three types of shoppers will get the most value here:

• DIY pool owners who handle their own maintenance and want OEM-equivalent quality without the Hayward brand markup
• Seasonal users who need one reliable filter per summer and don’t want to think about it again
• Anyone replacing a genuine Hayward C-4025 who’s tired of paying dealer prices for the same specs

Skip it if you’re the type who wants dealer-installed OEM parts for warranty purposes, or if you need a gasket included — buy that separately.

FAQ

Q: Will this work in my Hayward C4025 housing? A: Yes. The PA106-PAK4 matches the C4025’s dimensions exactly — 7.75" diameter, 23.5" height, 36 sq ft of filter area. It fits C4030, C4020, and C4025 models without modification.

Q: How often should I replace this filter? A: For a typical residential pool running 8-10 hours daily, plan on replacing every 1-2 seasons. Clean it monthly with a hose to extend life. If you see water bypassing the pleats or the cartridge looks misshapen, replace it sooner.

Q: Is this actually as good as the Hayward brand? A: Based on buyer feedback, yes. The filtration media and construction are comparable, and at a lower price point. The main difference is the slightly stiffer pleats and the missing gasket.

The verdict

The PA106-PAK4 delivers exactly what pool owners need: a drop-in replacement that filters effectively, fits correctly, and lasts a full season. It’s not flashy, but it doesn’t need to be. The minor annoyances — no gasket, snug fit, basic packaging — are tradeoffs you accept for the price savings.

Buy it if you want OEM-quality filtration without the OEM markup. Skip it if you need a gasket included or prefer dealer-installed parts.

Rating: 4.6/5 — a solid, dependable replacement that does its job without drama.

Where to Buy

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Last updated: 2026-08-06. Ratings and prices current as of review date. Verify on Amazon before purchasing.