Swimming in perfectly warm water is one of the great pleasures of pool ownership. A solar pool cover — also called a solar blanket or isothermal cover — lets you maintain that warmth without relying on an electric heating system. Here's everything you need to know.
What Is a Solar Pool Cover?
Unlike a winter cover, a solar cover is thinner and designed to let the sun's rays pass through while trapping the heat below. It offers several key advantages:
- Debris protection: keeps leaves, branches, and dust out of the water.
- Cleaner water: reduces how often you need to use cleaning and treatment products.
- Safety: helps reduce drowning risk for young children and pets when the pool is not in use.
- Heat retention: acts like an insulating layer to prevent heat loss, maintaining water temperature overnight and between sunny periods.
Ecological and Economic Benefits
A solar cover uses free solar energy to raise water temperature — reducing energy costs significantly. Even when used alongside a heating system, it makes your setup more environmentally friendly and more efficient.
The Two Main Types of Solar Pool Cover
1. Bubble Solar Cover (Isothermal Cover)
Made from thin polyethylene with an air-bubble structure, similar to bubble wrap. Available in rectangular, square, or custom shapes — and can be paired with a reel for easy handling. At around 150 microns thick, it reduces thermal evaporation, saves water, and limits the use of treatment products. Can raise water temperature by up to 9°F (5°C) after sun exposure.
2. Solar Rings
Composed of two vinyl film layers that capture and transmit solar heat. Hot air trapped between the layers improves thermal efficiency. Available in three main models: simple rings (lightweight and economical), rings with an anchoring system (more secure positioning), and "cover" rings (suitable for above-ground pools and spas).
Why Choose a Solar Pool Cover?
In summary: fewer chemicals, easy installation, compatible with all pool types (in-ground and above-ground), and effective prevention of algae and mold buildup. A solar cover is one of the most cost-effective and eco-friendly upgrades any pool owner can make.
How to Install a Solar Pool Cover
It's simpler than you might think — watch the video below:
For more on pool maintenance, see also:
FAQ: Choosing a Solar Pool Cover
What is a solar pool cover for?
A solar cover (bubble wrap cover) is used to heat the pool water through the greenhouse effect created by its transparent air bubbles. It also reduces evaporation (up to 70% water saving) and limits contamination from external debris. A well-used solar cover can raise water temperature by 4 to 8°C.
What thickness solar cover should I choose for my pool?
Solar covers come in 300, 400 and 500 microns. A 400-micron cover offers the best durability-to-price ratio for family use. 500 microns are more robust and last longer (4–6 seasons vs 2–4 seasons for 300 microns). Transparent bubbles heat more effectively than blue-tinted bubbles.
How do I cut and fit a solar cover to my pool shape?
For rectangular pools, cut directly to size with scissors or a long-bladed cutter following a pre-drawn line (masking tape). For oval or round pools, cut following the inner contour of the basin on the unrolled cover. A slight over-coverage (5–10 cm) is preferable to optimise insulation.
Should I remove the solar cover before swimming?
Yes, always remove the solar cover before swimming. Leaving it in place during use is dangerous (risk of being trapped under the cover). Also, chemicals added during treatment can degrade the cover if it is present. Use a cover reel to make the operation quick and easy (removal in 2–3 minutes).
How long does a solar pool cover last?
A solar cover's lifespan depends on thickness and maintenance: 2 to 3 seasons for 300-micron models, 3 to 5 seasons for 400 microns, 5 to 7 seasons for 500 microns. Store it rolled on its reel, in the shade, between uses. Sunlight and chlorine are its main enemies.
