Insulating covers for above-ground pools

Thermal covers for above-ground pools work through a layer of polyethylene bubbles that has a dual technical effect on the water's surface:

• Solar absorption: during direct sunlight, the sealed chamber in each bubble creates a magnifying-glass effect, raising the temperature by 3 °C to 6 °C.
• Thermal insulation: in the evening, the polyethylene layer slows heat loss overnight through contact with the cold outside air.
• Physical barrier: almost completely prevents water evaporation, reducing water consumption and the need to replenish chlorine or adjusters.

This system floats freely and does not rely on the pool's outer edge.

The bubble side should always face down, in direct contact with the water, while the smooth side should face up toward the sky. This setup allows the air trapped in the hemispheres to transfer heat to the water by conduction and keeps the cover afloat. If you place the smooth side against the water, sunlight is reflected inefficiently and the cover loses its insulating capacity. To make the cover easier to handle on round or oval pools, you can attach a compatible Manual cover reel for above-ground pools.

The thickness of solar covers is measured in microns and determines their structural durability and insulating capacity:

• 180 to 200 microns: a very lightweight option recommended for small, temporary pools that are set up for just two months in summer.
• 400 microns: a professional standard offering high mechanical resistance to UV degradation and better heat retention overnight.

A thickness of 400 microns extends its lifespan to three to five seasons, making it a worthwhile investment compared with thinner models that suffer premature bubble breakage.

You must remove the solar cover completely before applying a shock chlorine treatment and wait at least 24 hours before putting it back on the pool. During an intense oxidizing treatment, chlorine gas accumulating beneath the cover irreversibly degrades the extruded polyethylene polymers, causing the bubbles to become brittle and break down within a few weeks. Leave the pool uncovered with the filtration system running until the sanitizer level drops to normal values of between 1 and 2 ppm. Storing the cover in the shade during this process helps preserve its durability.

Yes, polyethylene solar covers can easily be trimmed with household scissors to fit the exact shape of the pool’s interior. For a precise cut, spread the cover over the water on a sunny day so the material can lose the folds from the packaging and expand naturally. Once it fits the shape of the walls, trim the excess, leaving a gap of two centimeters from the perimeter liner. This gap prevents the edges from rubbing against the PVC wall and allows the cover to rise and fall with changes in the water level.

A solar cover retains the heat gained and adds between 3 °C and 6 °C in direct sunlight, but if you want to extend the swimming season into spring or fall, you need an active heating system. The most efficient setup for above-ground pools is to install a Gre AR2069 solar heating system for above-ground pools in the return circuit and keep the surface protected with the floating cover at night. Without the cover, any heat supplied by panels or heaters will be lost within a few hours through evaporation as the ambient temperature drops.

A solar cover should not be used as a winter cover because it cannot withstand the weight of rainwater or prolonged exposure to UV radiation while stationary. If you leave the bubble cover on during winter, frost will freeze the plastic, and the buildup of rotting leaves on the surface will destroy the polymer. At the end of the swimming season, clean and dry your cover before storing it away from the sun, and replace it with a Winter cover for 4x3-meter pools or the size that matches your model, secured with perimeter cables tightened against the outer wall.