Prairie Dunes Firm Waterbed Insert



Try something different, like a normal mattress built to drop into your waterbed. Introducing the Prairie Dunes Firm Waterbed Insert, the water mattress alternative.


  1. Custom mattress built to fit your waterbed.
  2. Drops right into your existing wood frame water bed.
  3. Keep your under-bed storage drawer pedestal.
  4. You will love making your bed again.
  5. Keep your matching bedroom furniture.
  6. Utilize your existing bedding. 
  7. No more filling, draining, filling or waterbed treatment is required.

It’s the ordinary, extraordinary, plain old mattress made to fit right inside your old waterbed frame. The Prairie Dunes Firm Waterbed Insert is Therapedic’s solution to your old waterbed woes.


Learn more in our details section below.
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Prairie Dunes Firm Waterbed Insert. It Fits In Your Waterbed!


Why purchase an expensive new mattress set, bed, furniture, and bedding when there is a smart less expensive alternative? Instead of getting rid of your old waterbed consider a cheaper alternative solution. A Prairie Dunes Firm Waterbed Insert. A waterbed insert is a replacement mattress made specially to fit inside your current waterbed frame and is built with long-lasting tempered steel coil springs. No more water!


The Prairie Dunes Firm Waterbed Insert offers premium firm head-to-toe support for the entire body and tops off this support system with luxurious firm upholstery that doesn’t feel mushy, while also not feeling way too firm. The firmness is more of an old-school firm mattress. Usually not ideal for someone that is transitioning from water back to a traditional mattress. This is for someone that is used to a hard firm supportive mattress.


For example, this is replacing a waterbed insert, you are used to a firm innerspring mattress or you really do not like the soft waterbed feel that it once had. Something else that is very unique, is that this particular design unlike competitor models includes 2 sides. Mattress history shows us that two sides are always better than one! The Prairie Dunes Firm Replacement Mattress will last longer than comparable 1 sided beds.


Another interesting and useful feature is that is designed to leave just enough space for your hands for easy making of your bedding for everyday convenience.


Did We Mention The Benefits

  • Two Sided
  • Flip it over
  • Spin it around – end to end
  • Double-sided
  • Turn it over


Featured Mattress Firmness: Prairie Dunes Firm Waterbed Insert


Firmness Rating: 8

This waterbed mattress insert offers a solid core of firm support, enhanced with a touch of extra cushioning to soften the inherent firmness of its throwback coil springs. It has the perfect balance, ensuring the mattress is neither excessively hard nor overly soft. Positioned ideally in the middle of the firmness spectrum, it provides a comfortable and supportive sleep experience. Popular for those seeking quality within a budget, this mattress is a favored choice for its balanced comfort and affordability.


Understanding Mattress Firmness: A Quick Guide Of Our Firmness Rating Overview (1-10 Scale):


Firmness For Water Mattresses:

1: Ultra-Soft, our softest option. Imagine lying on a gently bobbing boat; this is our softest, cloud-like water mattress.
4: Firm, the firmest among water mattresses. This is where water meets firmness – still with that gentle water feel, but with maximum support.


Firmness For Coil Spring Mattresses:

5: Firm, marking the entry point into our coil spring range. It’s firmer than our firmest water mattress but maintains a gentle feel, providing a nice balance for those transitioning from water to coil spring mattresses.
10: Ultra Firm, the hardest mattress we offer. The epitome of firmness; think of lying on a firm, supportive surface that holds you perfectly without any sink.


Here Are Some Of Our Other Waterbed Mattress Inserts



Waterbed Replacement Mattresses


Are you fed up with your really heavy waterbed mattress that leaks when you least expect it? Whatever your reasoning for getting off of water you will want to consider keeping your waterbed frame, but doing away with your water mattress. The solution is a Prairie Dunes firm Waterbed Insert. It is a replacement insert mattress specially designed by Therapedic® to drop down into your current waterbed.


It is constructed with heavy-duty coil springs and features a cushier plush surface that is better for those just coming off of a softer-feeling water mattress. The Bedding Group & Therapedic® builds this luxurious support system and custom-made it to fit the 3 standard waterbed sizes: Super Single, California Queen, and California King wood frame waterbed you already have. No need to buy a headboard, frame, or sheets.


Remove your old water mattress and heater and Simply place the new mattress inside the bed frame cavity and begin to experience its convenience. Keep all your furniture, waterbed frame, and bedding. It is slightly undersized around all four sides for better fit and easy making. It is just that easy. Our two-sided feature will extend mattress life giving you more value for the dollar.

Additional information

Dimensions N/A

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Product Features

Prairie Dunes Firm Waterbed Insert Construction Features


Fabric: Knit


  •  FR Safe Fiber
  • 1″ Therasoft Foam
  • 1/2″ Polyurethane Foam

Pillow Top: NA


  • 3/4″  Heavy Density Foam
  • Insulator Liner

Support System:

  • 504 Alternating VertiCoil Edge
  • 13.75 Gauge Steel Coil Wire

Coil Counts Are For Regular Mattress Sizes And Are Used To Illustrate What Style Coil Unit Has Been Modified

  • Twin–286
  • Full–396
  • Queen–504
  • King–648

Prairie Dunes Firm Waterbed Mattress Insert Measurements / Sizes


Mattress Height

  • Total Thickness From Top to Bottom–Approx. 9.5″
  • Tape Edge to Tape Edge–8″

Super Single Waterbed Frame

  • Cavity Measures 48 wide X 84 long
  • Water Bed Mattress Replacement Insert Measures 46 wide x 82 long

California Queen Waterbed Frame

  • Cavity Measures 60 wide X 84 long
  • Water Bed Mattress Replacement Insert Measures 58 wide x 82 long

California King Waterbed Frame

  • Cavity Measures 72 wide X 84 long
  • Water Bed Mattress Replacement Insert Measures 70 wide x 82 long

Warranty–10 Year

Photo for illustration purposes. Fabric color may vary from the actual photo.

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