Do canopy weights work in a pool?

Pop-up canopies usually ship with one of two weight systems: nylon bags you fill with sand or PVC tubes you fill with water. Both work fine on grass and concrete. Neither works in a pool.

Why sandbags fail underwater

Sand weighs about 100 pounds per cubic foot in air. Submerged in water, that drops to about 60 pounds because the water displaces the sand grains. A 25-pound sandbag in air is more like a 15-pound sandbag in the pool. Then add the fact that the canopy leg can lift the bag, since water makes everything float-prone, and you have an anchor that doesn't really anchor.

Why water-fill tubes fail underwater

This one is obvious in hindsight: a tube of water has zero net weight when it's already in water. Water doesn't pull water down. The tubes do nothing.

What actually works

You need a system that anchors the canopy from inside the leg itself — not by hanging weight off it. Canopy Turtles do exactly that. Each Turtle has a sealed sand pocket built into the shell. Fill it once, bolt it onto the leg, and the weight stays exactly where it needs to be: at the bottom of the canopy frame, low and centered, where it can plant the canopy against any normal pool-day breeze.

Bonus: the smooth ABS underside protects the liner and plaster from the same canopy feet you used to worry about.