Lower the water, blow the lines, cover it.

Yes, you can winterize a pool without draining fully — in fact, that’s the standard method. Draining a pool completely can actually cause major problems (popped liner, cracked shell if ground water pushes up). So don’t do that.

Here’s the short version: Lower the water level to below the skimmer (usually around 6-12 inches depending on your setup). Then blow out the return lines and skimmer lines with a shop vac or compressor until all water is out. Plug the lines before removing the vac so they stay dry. Add winterizing chemicals (algaecide, maybe a floater with tablets). Then put the cover on.

The tricky part is making sure you get all the water out of the lines. If you leave a pocket, it freezes and cracks the pipe. A plug that fits properly is worth the few bucks. Also, if you have a heater or pump, you’ll need to drain those separately.

That’s basically it. The pool stays mostly full, the equipment stays winterized, and you don’t gamble with a flood in the spring.