Water-resistant & lightweight
AirLoc™ panels have no foam core to soak up water, so the cover weighs the same out of the box and years later: 35–40 lb, depending on size.
Learn about water resistanceSpa Fitter
Home and Garden Spas HG51 Replacement Cover
The Home and Garden Spas HG51 takes the AIRCAP 1™ X-Small — a foam-free replacement hot tub cover for square spas 80"–82". The HG51's cabinet measures 80" x 80", inside the X-Small's range. The cover weighs 35–40 lb for life, costs $1,195, is engineered to comply with ASTM F1346-23, and carries a 3-year limited warranty.
Your size: AIRCAP 1 X-Small
Cabinet 80" x 80" fits 80"–82"
AIRCAP 1™ is a foam-free hot tub cover: rigid AirLoc™ air panels with no foam core to waterlog, a light 35–40 lb.
$1,195 with free shipping, usually at your front door within 3–5 business days.
Wrong size? Swap it or return it within 30 days of delivery. We pay return shipping. How it works (fit guarantee)
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3-year limited warranty · In 100+ hot tub showrooms
AIRCAP 1™Made for a lighter lift.
AIRCAP 1™ X-Small · Home and Garden Spas HG51
Buy the X-SmallFit at a glance
| Spa cabinet | 80" x 80" |
|---|---|
| AIRCAP 1™ size | X-Small fits 80"–82" |
| Cover weight | 35–40 lb — constant for life |
| Price | $1,195, free US shipping |
| Skirt | ZipTech™ modular, three lengths included |
| Safety | Engineered to comply with ASTM F1346-23 |
| Warranty | 3-year limited warranty |
Measure straight across the top of your spa, edge to edge, both ways, in inches.
Watch it open and close on a cover lifter
Why the X-Small fits the HG51
The AIRCAP 1™ comes in six sizes covering square spas from 77" to 94". Each size is built to overhang its band slightly — that is how a spa cover is meant to sit — so the X-Small, which fits cabinets 80"–82", covers the HG51's 80" x 80" shell with the right overhang.
At 80" the HG51 sits at the bottom of the X-Small's 80"–82" range, so there is room to spare: the same cover fits anything up to 82". No other Home and Garden Spas model in the Spa Fitter has the HG51's 80" x 80" cabinet. The 5 Home and Garden Spas models we fit sit on 3 footprints, and the HG51 is on the smallest of them; together they span 2 of the six AIRCAP 1 sizes.
Cabinet dimensions can change between model years. Before ordering, measure your HG51 at its widest point across the top, in both directions, including any acrylic lip that overhangs the cabinet — the SureFit™ guide walks through it in two measurements. If a figure you have found elsewhere is larger than ours, an overhanging lip is the usual reason. If your spa measures between two sizes, round up.
Every spa in our catalogue that measures 80" x 80" is on one page: hot tubs that take an 80" × 80" cover — the same AIRCAP 1™ X-Small, at the same price.
Where this measurement comes from
Dimensions are taken from each product page’s specification list and its dimensions table, which agree (September 2026). We publish the figure the maker publishes, and we say so — if your own tape disagrees with it, trust the tape and measure in two steps.
How the AIRCAP 1™ is built
Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction: a sealed air chamber with no foam to absorb water, so it does not become the waterlogged two-person lift that ends most foam covers. More on how it insulates, how it holds up, and why it is foam-free — or estimate what your current foam cover weighs.
What customers are saying
Awesome product, my kids don’t complain about the cover anymore…
Best $$ I ever spent!
What this company has created in terms of an original and revolutionary product is nothing short of amazing.
For a reasonable price, I can cover my spa with a top that won’t get musty.
Nice and lightweight
…set up was super easy and took about 15 min total.
Installation was a breeze and we love it already!
Great customer service still matters, and frankly, not enough companies deliver it anymore. This company does, and that deserves recognition.
Do not wait to buy one.
01 / 09
Thoughtfully engineered
Built to solve the
problems of foam.
Three practical reasons to rethink your next hot tub cover.
Consistent insulation
The sealed AirLoc™ air core has nothing in it to absorb water, so its insulation stays consistent for the life of the cover.
See how AIRCAP insulatesReplaceable skirt system
Three ZipTech™ skirt lengths come in the box, and a worn or damaged skirt can be replaced on its own, without replacing the whole cover.
See how ZipTech worksEvery detail matters
Purchase with confidence.
30-day returns
Fits or we make it right. Wrong size or changed your mind? Swap it or return it within 30 days of delivery. We send a prepaid return label and there’s no restocking fee. Covers must come back in like-new condition with all parts. Bought from an authorized retailer? That retailer’s return policy applies.
How the fit guarantee works3-year limited warranty
Backed by a three-year limited warranty against manufacturing defects.
Warranty detailsFit assistance
Use Spa Fitter™ or SureFit™, or contact us before you order and we will confirm your size.
Get fit helpHome and Garden Spas HG51 cover: common questions
Need help? Contact thrml. to confirm your fit before you order.
What size hot tub cover fits the Home and Garden Spas HG51?
The Home and Garden Spas HG51 takes the AIRCAP 1 X-Small, which fits square hot tubs measuring 80"–82" across. The HG51's cabinet measures 80" x 80", inside that band. Measure your spa side to side across the top of the cabinet to confirm before ordering.
Will the AIRCAP 1 fit a Home and Garden Spas HG51?
Yes — the HG51's 80" x 80" square cabinet falls in the AIRCAP 1 X-Small's 80"–82" range, and the ZipTech modular skirt system ships with three skirt lengths so the drop over the cabinet adjusts without a custom order. Cabinet sizes can change between model years, so confirm with two quick measurements.
How much does a replacement cover for the Home and Garden Spas HG51 cost?
The AIRCAP 1 costs $1,195 in every size, including the pump, three ZipTech skirt lengths, and tie-down straps, with free US shipping and 30-day returns. Unlike a foam cover it has no foam core to waterlog, so it stays at its original 35–40 lb weight for life.
How heavy is a replacement cover for the Home and Garden Spas HG51?
The AIRCAP 1 X-Small weighs 35–40 lb and keeps that weight permanently — its sealed drop-stitch air core cannot absorb water. A foam cover starts at 40–75 lb and gains weight as the foam saturates.
5 Home and Garden Spas models
Every Home and Garden Spas model we fit
Your cover. Your way.
Not the HG51?
The Spa Fitter matches the current models of every major brand to the right AIRCAP 1™ — or measure any square spa with SureFit™.
Prefer to shop locally? Find one of 100+ showrooms.
Available in over 120 authorized hot tub showrooms across 34 states.