A solid pool cover is the only real solution.

Yes, you can cut evaporation by 90% or more with a cover. Everything else is a marginal improvement.

The physics is simple: water doesn’t evaporate into air — it evaporates into moving air. A cover blocks the surface from wind and sun. Without it, you’re losing about a quarter-inch of water per day in hot, dry weather. That adds up fast.

Liquid “covers” (monomolecular layers) help a little, but they’re a scam compared to a real cover. They break up from wind and swimmers, need reapplying, and don’t help at night. Solid covers also keep debris out and heat the water if you get a solar cover.

If you can’t cover the pool (aesthetics, kids, whatever), your next best bets are wind breaks (fences, hedges) and shading the water with trees or a sail. But you’re still losing water. A cover is cheap compared to the water bill.

Get the cover. Your water table will thank you.