If you enjoy swimming and want to extend your swimming season from the beginning in spring to later in autumn, sun-pool covers may be an economical way to do this. Now the solar pool cover won't keep the water as warm as a pool heater, but it will definitely help keep the heat in the pool.
The solar pool cover is basically a giant sheet of bubble wrap that you put in the pool to help heat the water, faster, and keep it warm. You put a cover on at night to keep warm and take it off in the morning so the sun can warm the water again. You can buy custom retractable pool enclosures for indoor outdoor pools from various online sources.
Doing this every night for days or weeks will warm your water faster than if it is not used. This will start your swimming season a little early in spring and if you repeat it in autumn, it will extend your swimming season too.
The only hassle with this solar pool cover is taking it off and storing it during the day. Because they are a giant sheet, they are difficult to handle. You can buy a giant roller to roll up the sheets, but the price is expensive.
A solar pool cover is a must if you want to swim early or just want warm water. If you decide on a sun cover, find one in your size online and order it there. You will save a little money. Just get the dimensions of your pool and then buy a slightly larger size.
You can easily cut the "bubble wrap" sun cover to whatever size you want. In fact, if you cut it exactly the same size as your pool, it is easier to put it on the water and keep it in a better place.