Waterbeds were so popular years ago it seemed as if everyone had one. Today, many people are finding their waterbed isn't as comfortable as they once thought or their waterbed mattress is old and needs to be replaced. One answer is to change that old waterbed into a conventional bed. Converting a waterbed to a regular bed isn't difficult if you follow these steps.
Measure the length and width of your bed. Measure the depth of the wood sidewalls. This is the starting point to finding a mattress that fits inside the sidewalls.
A regular king-size mattress will usually fit a king-size waterbed frame; likewise for a queen-size mattress. A California king is a special size many stores do not carry; it will have to be ordered.
Buy an all-in-one mattress. This means the mattress doesn't need a box spring. The depth of most waterbed frames is 9 ½ inches--not deep enough for a box spring and a mattress. A mattress that is supported without a box spring is just high enough to fit inside a waterbed frame. A pillow top mattress will add additional inches.
Drain the waterbed mattress and remove it. Remove the liner. Vacuum out the boxed frame. Lay the mattress in the frame. You may have extra room on the ends and on each side, but not enough to make a difference.
Use your waterbed sheets or buy new regular mattress sheets. In most cases, waterbed sheets will fit, but may not reach all the way underneath in the corners.