To avoid Hypnos mattress problems such as uneven settlement, your mattress should be turned once every 3 - 6 months.
This will help to encourage even settlement and prevent your mattress from dipping.
Some Hypnos mattresses may also need to be flipped.
You should check the care instructions for your particular Hypnos mattress.
Alternatively, you could consider a Hypnos Luxury No Turn mattress that doesn’t need to be rotated or flipped.