To even out the wear, flip the mattress over and reverse it end-to-end every three weeks tor three months – and every couple of months thereafter.
Mattresses are surprisingly heavy; two people should do this to avert damage to the mattress and your back! Vacuum the mattress once a month.
Also, let it breathe for 10-15 minutes’-every day before making the bed – remove the bottom sheet and all bedding and keep aside.
Air mattresses thoroughly once in a while.