Waterbeds offer many advantages over conventional mattresses — they not only relieve pressure on the spine but also on the entire body, adapting to every sleeping position in an optimal and pressure-relieving way. That’s why sleeping in a waterbed is often described as weightless, almost floating. But doesn’t weightless sleep mean lying on an unstable surface full of water — and could that even make someone seasick?
Both of these concerns can be clearly answered with a “no.” But how do we at bellvita ensure that you sleep weightlessly on a waterbed without excessive motion or feeling like you're lying on a bag of water?
If you don’t want to read the entire text — which we recommend — you can jump directly to the desired section by clicking below:
- Why do waterbeds have stabilization layers?
- What stabilization levels are available at bellvita?
- Is the water fill level important for stabilization?
- Can I adjust the stabilization by changing the water fill level?
- Which stabilization level is right for me?
- Stabilization by body weight?
- Which stabilization is suitable for seniors?
- Which stabilization after disc surgery?
- Is there lumbar support in the waterbed?
- Different stabilizations in DUAL waterbeds
- At bellvita, you always rest on safe stabilization!
Why do waterbeds have stabilization layers?
The answer is surprisingly simple: to calm the water movement in a waterbed — that is, to dampen the wave motion — special foam layers are built into the water chamber. These layers are called stabilization layers or baffles and reduce water movement in the bed. Without stabilization, your body would rock back and forth when you lie down. That’s not necessarily a bad thing — experienced waterbed sleepers often enjoy this complete feeling of weightlessness. A waterbed without any stabilization is referred to as “free flow.” This is the most original form of a waterbed, dating back to ancient versions made with goat skins filled with warm water, and also the type used during the waterbed boom in the 1980s.
However, many people still associate this type of bed with mixed feelings. While the sleep experience is pleasant, it's harder to find the right water fill level — even a weight change of more than 2 kg would technically require an adjustment. A free-flow bed is very sensitive. Turning or getting out of bed can also be more difficult. For these reasons, we do not recommend a free-flow bed for beginners. The adjustment period is significantly longer than with a fully stabilized waterbed. A waterbed is never firm — claims of “100% firm” or more are a myth! The key benefit of a waterbed is that your body sinks in, and the warm water adapts perfectly to your body shape.
What stabilization levels are available at bellvita?
We offer a total of eight stabilization levels for our bellvita waterbeds. Up to 7 layers of our special waterbed fleece — also called fiber mats — are inserted into the water chamber and welded in using high-frequency technology. Even one single fleece layer reduces the wave motion time of a free-flow waterbed by more than half. When you lie down, the water will move for just 5–8 seconds. This motion is known as wave motion time. At bellvita, we measure stabilization using a 60 kg weight in a 180×200 cm bed with optimized water fill. The stabilization level is labeled with an “F” (e.g. F1), where “F” stands for “flow.”
Unfortunately, there is no official standard, so the measured wave motion time may vary slightly between manufacturers. It also varies with body weight and the water fill level. A second fleece layer reduces the motion to 3–4 seconds and is called F2. Our best-selling version is F4, which has 90% stabilization and approximately 1 second of wave motion.
Here is an overview of bellvita’s stabilization levels:
- 0% = approx. 9–12 sec. motion / 0 fleece layers
- 30% = approx. 5–8 sec. motion / 1 fleece layer
- 50% = approx. 3–4 sec. motion / 2 fleece layers
- 70% = approx. 1–2 sec. motion / 3 fleece layers
- 90% = approx. 1 sec. motion / 4 fleece layers
- 95% = approx. 0.5–1 sec. motion / 5 fleece layers
- 98% = under 0.5 sec. motion / 6 fleece layers
- 100% = approx. 0 sec. motion / 7 fleece layers
But how do you determine the right stabilization level for your new waterbed when it's influenced by so many factors — not just the number of fleece layers, but also your body weight, the correct water fill level, and even the bed size you choose?
Is the water fill level crucial for a waterbed’s stabilization level?
Even trying out a waterbed in a waterbed showroom or spending a night on one in a hotel rarely leads to a truly reliable decision — because no one will take the time to adjust every bed and stabilization level to your needs and precisely match the water fill level to you. Yet this is essential for your well-being! At bellvita, we come to your home and determine the optimal fill level together with you. Our experienced installers support you throughout the process. We don’t use standard formulas or charts — we determine the water level based on bed size, body weight, your build, and especially your comfort preferences. An athletic 80 kg body requires a different setting than someone else with the same weight but a different shape. Do you want to sink in softly or prefer it slightly firmer? That depends on the stabilization. The correct water fill level is critical for restful sleep. We also consider your sleeping position — side, stomach…? Most people don’t actually sleep on their backs, even though that’s how most people test mattresses in stores.
You can test waterbeds in nearly any showroom. But without standardized labels for stabilization levels — and with some manufacturers using up to 12 thinner fleece layers instead of 7 — it's easy to get confused. Ask the salesperson about the wave motion time in seconds, as that’s often the only consistent benchmark for comparing waterbeds across brands. If the water fill level doesn’t feel right, don’t hesitate to ask for it to be adjusted.
Can I adjust the stabilization of my waterbed by changing the water fill level?
Yes! Here's a simple trick to simulate the correct fill level:
Usually, just a few liters make a big difference. Your waterbed specialist can simulate this by applying pressure in various spots on the mattress. The rule is simple: you must lie straight and sink in evenly. You shouldn’t be on a mound — that would mean too much water — and you definitely shouldn’t sag in the hip area.
This simple technique can be used anytime to re-adjust your bed — for example, after weight loss or gain. Unlike conventional mattresses, waterbeds adapt continuously to your body. That’s why they are especially popular during pregnancy. Even in the later stages, pregnant people can lie on their stomach without discomfort thanks to the absence of pressure points.
Another very practical method is simply changing the actual water level. And don’t worry — you won’t need buckets. Just a few liters make a difference and can easily be added or removed using a measuring cup. In the following example, our technician removes excess water using a standard household measuring cup.
And here, our technician refills the waterbed — again using a measuring cup.
He then vents the waterbed to remove any air that got in during filling — either manually, or using a pump or vent valve — to eliminate gurgling sounds. After all, you want to lie on water, not on trapped air.
Then it’s time for another test: are you lying comfortably and sinking in evenly? If not, repeat the process in steps of one liter. You’ll likely find the perfect level after just a few tries. Having a second person view your posture from the side is helpful — sometimes our own perception differs from reality. That’s why we usually deliver our bellvita waterbeds with setup and adjustment performed by our trained installation team.
Which stabilization level is right for me?
So far, we haven’t answered the key question: is F1, F6, or even F7 the right stabilization level for you? If you’ve read this far, you’ve probably realized — there is no single “correct” level. The ideal choice depends on many factors: bed size, your weight, the water fill level, and — most importantly — your personal preference and sleep needs.
If you enjoy a softer sleep experience and want to sink more deeply into the cozy waterbed, choose a lower stabilization level. If you prefer a "firmer" feel (though, as we’ve explained, waterbeds are never truly firm but rather weightless), then opt for a higher level.
If the water core of the mattress is filled with more water and is thus firmer, this is often perceived as “harder.” If it’s filled with less water — like a not fully inflated balloon — it feels softer. But be careful: you should not sag in the waterbed or lie on a “water hill,” as this can lead to back or neck pain. That’s why the stabilization times for waterbeds are always given as a range! This reflects the minimum and maximum fill levels for the mattress, which also depend on the sleeper’s weight and bed size — both of which significantly influence the stabilization time.
Stabilization level based on body weight
Can the stabilization level be determined by your body weight? Yes and no. As a manufacturer with years of experience and thousands of installed waterbeds, we can offer helpful recommendations through our trained installation team. For example, we usually recommend a higher stabilization level for heavier individuals, such as someone weighing 130 kg. But here’s the nuance: with a conventional mattress, the person’s weight causes uncomfortable pressure, and the sleeper keeps changing position — which can cause limbs to go numb. A waterbed is different: you can lean on your elbows for hours and still feel no discomfort. That’s why, in some cases, less stabilization may even be better for heavier individuals.
However, we generally recommend a higher stabilization level — 90% or more (F4 or higher). That’s because determining the correct water level in a free-flow bed is tricky, and even small weight changes require refilling. Turning over or getting up is also more difficult in a free-flow bed. Additionally, most people need time to get used to the feeling of sleeping on water — especially if they are switching from a firm mattress. This adjustment takes time, and for beginners, we usually suggest a higher stabilization level, especially since fleece layers also offer extra support when sitting down. Heavier individuals need more support; lighter sleepers need fewer fleece layers. This is somewhat comparable to the firmness ratings of conventional mattresses — although with waterbeds, "less is often more."
What stabilization is suitable for seniors?
Keep in mind that getting out of bed may become more difficult with age. Therefore, we recommend higher stabilization levels for seniors — regardless of weight — and choosing waterbeds with comfort-height access. This is only a recommendation based on years of experience in manufacturing and installing waterbeds. Here’s a quick tip: experienced waterbed users tend to prefer 30%–50% stabilization, while beginners often choose 70%–95%. Our best-selling level is 90%, as it still offers the waterbed feeling with minimal wave motion. For individuals over 130 kg, we recommend 98% or even 100% stabilization. This ensures the mattress still adapts well to the body, despite the weight.
What stabilization is recommended after disc surgery?
Many people choose a waterbed after years of sleeping on a conventional mattress — often due to back pain. In our experience, a pressure-relieving and temperature-controlled waterbed is ideal in such cases. If you’ve had a herniated disc or surgery, we also recommend a high stabilization level, as the wave motion of a lightly stabilized bed may be counterproductive. In such cases, lumbar support may make sense.
Is there lumbar support in a waterbed?
Remember: less stabilization is often more — but only once you’ve adjusted to the waterbed. Give yourself time. If you're torn between two stabilization levels, we encourage you to choose the lower one. You’ll likely adapt quickly. Since wave motion time can be fine-tuned via water fill level, many stabilization levels overlap. If extra support in the lumbar area is needed, we can add a horizontal fleece layer for reinforcement. This keeps your hips level and prevents excessive sinking. For very overweight individuals, this may be helpful depending on body shape. But keep in mind: waterbeds are designed for “weightless” sleep. You don’t want too much added support that mimics a car seat’s lumbar feature. As a manufacturer, we generally do not recommend additional lumbar support in waterbeds.
Different stabilization levels in a dual waterbed
If two people sleep in a waterbed, we recommend a dual system — two separate water chambers in one bed. The divider in the center prevents wave motion from transferring from one side to the other. This allows (and in the case of different body weights, encourages) choosing different stabilization levels for each side. Problems arise only when the difference is extreme — e.g., F0 (free flow) on one side and F7 (100%) on the other. In that case, you may feel like you’re falling into a “weightless hole” when turning over. We recommend a maximum difference of 2 stabilization levels between both sides.