california: What is the difference? I now have a REGULAR mattress that is a california king size. I have ordered a california king size WATERBED mattress. Yes, I have the right type bed, etc. for a waterbed. Can I just use my same sheets or must I order waterbed sheets? The only thing that I can think of is that they are sewn together at the bottom. Is the size or fit any different?|||My best guess--and that's all it is, a guess--is that your existing sheets should be fine. The only potential I see for problems is if the depth of the waterbed is substantially more than your existing regular mattress, so the waterbed requires deep pocket sheets that your old bed doesn't. (We had that problem replacing an old bed with a new one of the same size--but so much deeper none of our bottom sheets would go on at all.) You can always stitch them together if you prefer that. It would be easy.