Replacing sagging layers

Hi, My husband and I purchased the Flo-Bed v-zone bed approximately 20 years ago and have been very happy with it. About 10 years ago my husband started complaining that his side wasn’t firm enough (he already had the firm layers), so flo-beds suggested we purchase a super firm layer which we did. He seemed ok with that. Now, 20 years later, our bed has two sagging sections more than an inch where we each sleep. Should we purchase all new layers, or just the top layer? I like a softer side, ( I am a side sleeper) but he prefers a firm as possible side as he is a back sleeper.
Thanks

Hi Abruzzigirl, it sounds like we should just replace the 2 sagging sections. If you’d like to start with just those sections, it makes since to me. Contact FloBeds via phone or email. We’ll take care of you.