Pool winterising in Mallorca: winter pool maintenance, covers and the mistakes that cost money

How to prepare your Mallorca villa pool for winter: when to close it, active or passive winterising, covers, salt chlorinators and what you should never do.

When the swimming season ends, many villa owners in Mallorca ask the same question: what do I do with the pool until spring? The short answer is that you neither drain it nor abandon it. The Mallorcan winter is mild, with frost very rare outside the Serra de Tramuntana, so the drastic winterising common in central Europe, with blown-out pipes and dismantled pumps, is not needed here. What is needed is a properly planned winter maintenance routine, because a pool left unattended from November to March reaches April with green water, limescale baked onto the waterline and, quite often, a damaged piece of equipment. The right moment to start is set by the water rather than the calendar: once its temperature settles below roughly 15 °C, algae almost stop growing and treatment can be reduced safely. In Mallorca that usually happens between mid-November and December; closing the pool earlier, while the water is still warm, is the most common reason for water going bad halfway through winter.

There are two ways to do it. With active winterising the system keeps running at a low level: filtration is cut to a few hours a day, a minimum level of sanitiser is maintained and a technician calls every two or three weeks to test the water and empty baskets and skimmers. This is the recommended option for most villas on the island, particularly if the house is used or rented in winter or if the pool is part of the view from the living room. With passive winterising the pool is shock-treated, the pH is adjusted, a winterising product with algaecide and scale inhibitor is added, the filter is cleaned thoroughly, the pool is closed under an opaque cover and filtration is stopped for weeks at a time. It saves electricity and visits, but it demands a good, well-tensioned cover and perfectly balanced water before closing; if light or leaves get in, the problem develops under the cover where nobody sees it. In both cases the first step is the same: a full clean of floor and walls, a backwash and rinse of the filter, and balanced pH, alkalinity and hardness.

The most expensive mistakes are repeated every year. The first is draining the pool: the water protects the shell against temperature swings and against ground pressure, and an empty pool can crack, shed mosaic tiles or deform its liner, as well as wasting water that is scarce on the island and subject to restrictions in drought years. The second is forgetting the salt chlorinator: in cold water the cell works under strain and wears out far sooner, which is why most manufacturers advise reducing output or switching the unit off below about 15 °C and moving to a minimal manual dose. The third is switching everything off and leaving, with nobody checking the water level after heavy autumn rain, the tension of the cover after a windstorm or the condition of the pump, which suffers if it sits idle for months in damp, salty air. And on the handful of nights when frost is forecast in higher or inland areas, it is enough to schedule filtration for the early hours so that moving water protects pipes and equipment.

As for cost, winter maintenance is noticeably cheaper than summer maintenance: fewer visits, less product and far fewer pump hours, so most companies apply a reduced low-season fee or a price per fortnightly visit. A winter cover is a separate investment that depends on the size and shape of the pool and pays for itself in chemicals, evaporated water and cleaning hours when you reopen. Compared with the cost of recovering green water, descaling a pool finish or replacing an electrolysis cell, proper winterising is one of the best-value services you can arrange for your villa. If you do not live on the island, the sensible approach is for the same technician who looks after the pool in summer to keep seeing it in winter and send you a short report with photos after each visit. At Mallorca VillaCare we connect you with trusted pool maintenance companies in your area, so the pool spends the winter protected and is ready for the first swim of spring.