A solar cover is the best for evaporation.

That floating bubble wrap stuff isn’t just for heating your pool. It cuts evaporation by something like 90% by physically blocking the water surface. Liquid pool covers (the chemical ones) do help, but way less—maybe 30%—and you have to keep reapplying.

Solid winter covers seal top to bottom, but that’s a pain to put on and take off. For everyday summer use where you just want to keep water in and heat in, solar cover wins.

Your water bill and heater will thank you.