How do you fix a peak bed mattress? We have a king bed to be exact peaking or bowing within...

We have a king bed to be exact peaking or bowing within the middle. We both sleep on the edges so the middle is starting to peak up. It is a pillowtop so we can't flip the mattress over and it can't be turned sideways because the mattress is not square. Any concept on how to fix it?
Answers:    The poor quality polyurethane foam used contained by many pillowtops fast degrades resulting within body depressions. One option is to cut sour the top layer and replace it next to a latex topper and a wool fleece pad.
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