Hot Spring Watkins Grandee Tri-X Replacement Filter Set of 5

The Verdict

If you own a Hot Spring Grandee, you already know the filter situation is non-negotiable. These aren’t universal-fit cartridges you can swap from a generic brand without consequences. The Watkins Tri-X filter is the engineered component your spa’s circulation system was designed around — and this five-pack is the most cost-effective way to keep a fresh one in rotation all year.

What’s actually in the box

You get five individually wrapped Tri-X filters, each measuring 7.5 inches in diameter with the standard 7-inch length for Grandee models. The packaging is straightforward — no frills, no accessories, just the filters. Each one is sealed to prevent contamination during shipping, which matters more than you’d think if you’ve ever received a dusty filter from a third-party seller.

The Tri-X material is the standout feature here. It’s a three-layer microfiber construction that traps particles down to 5-10 microns — noticeably finer than the standard 15-20 micron filtration you get from cheaper pleated options. As shown in the product image, the pleating is dense and uniform, which translates to more surface area for trapping debris.

Real-world performance

I’ve run these in a Grandee for six months, replacing on the standard 90-day cycle. The water clarity difference versus the previous generic filters I’d been using was apparent within the first week. The Tri-X media holds more particulates before pressure drops, which means your circulation pump works less and your heater runs more efficiently.

One thing I’ll note: these filters demand disciplined cleaning. The microfiber material clogs faster with oils and lotions than standard pleated filters. A monthly soak in a quality filter cleaner is non-negotiable if you want the full 90-day lifespan. Skip it, and you’ll see flow reduction by week six.

What buyers consistently report

The 4.7-star rating across 235 reviews reflects genuine satisfaction. One verified buyer noted: “These fit perfectly on my 2018 Grandee — no adapters, no shims, no wrestling. Dropped right in.” Another long-time owner mentioned: “I’ve tried the knockoffs. They leak around the seals. These don’t. Worth every penny.”

The most common praise centers on the OEM fit guarantee. Hot Spring’s filter housing has specific threading and seating requirements that generic filters often get wrong — causing bypass, where unfiltered water sneaks around the cartridge. That’s not a problem here.

Where it falls short

Let’s be direct about the drawbacks. The cost per filter is roughly 25-30% higher than compatible generics. You’re paying for the Watkins name and the engineering that comes with it. There’s also no included storage case — a minor annoyance if you’re cycling filters and need somewhere clean to keep spares.

The Tri-X material’s sensitivity to heavy chemical use is worth mentioning. If you run your sanitizer levels high or use non-chlorine shock frequently, you’ll see accelerated media breakdown. Stick to manufacturer-recommended chemical levels and these will last their rated lifespan.

Who should buy this

• Hot Spring Grandee owners — this is your filter, period. No reason to gamble on generics.
• Multi-spa households — with five filters, you can rotate two sets across multiple spas if you own other Hot Spring models that accept the same cartridge.
• Long-term spa owners — the bulk pricing makes sense if you’re already on a regular replacement schedule.

Skip it if you own a different spa brand, or if you’re willing to accept the bypass risk and reduced filtration of cheaper alternatives. Your water quality will reflect that choice.

FAQ

How often should I replace these filters? Every 90 days for normal residential use. If you have heavy bather load or frequent parties, drop that to 60 days. The Tri-X media will tell you it’s done when water flow from the jets noticeably decreases after cleaning.

Will these fit my Grandee model year? They fit all Grandee models from 2008 onward. Earlier models use a different cartridge — verify your filter part number against the 73250 designation before ordering.

Can I clean these instead of replacing? You can extend life with monthly chemical soaks, but the Tri-X media degrades after about six cleanings. That’s roughly 18 months of rotation. After that, replacement is cheaper than dealing with reduced filtration.

The Verdict

Buy it if: You own a Hot Spring Grandee and want OEM-grade filtration with proven fit — no adapters, no bypass, no guesswork. The five-pack pricing makes this the smartest way to maintain your spa’s water quality.

Skip it if: You’re on a tight budget and willing to risk generic filter compatibility, or if your spa is an older pre-2008 model that needs a different cartridge.

This is one of those rare products where paying for the brand name actually pays off — the engineering tolerances are real, and the filtration performance is measurable. For the price of one service call, you get a year of clean, properly filtered spa water.

Rating: 4.6/5 — loses half a star for the lack of storage case and the premium pricing, but the performance and fit are exactly what Grandee owners need.

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.