When should you reopen your pool?
Spring does not arrive at the same pace beside Lake Geneva, on the Swiss Plateau or at higher altitude. Look at the water temperature, local forecasts and the pool’s condition rather than fixing the same date every year. The aim is to act before warmer conditions encourage the water to deteriorate.
Technical guides often give reference temperatures of around 12 to 15 °C, with differences depending on the installation. For a salt chlorinator, also check the minimum operating temperature specified by the manufacturer. Cold water does not necessarily allow every device to be restarted.
After active or passive winterisation
After active winterisation, the circulation system has continued running at a reduced level. Equipment still needs inspecting, the pool needs cleaning and the schedule needs reviewing. A few hours of filtration in winter are not enough to prepare a pool for summer swimming.
After passive winterisation, reopening also involves reinstalling removed components and taking out winter protection. Plugs, floats, drain points and valves must be dealt with in an order suited to your installation. Keep manuals and, if possible, photographs taken in autumn close to hand.
Clean without sending dirt into the water
First remove leaves and debris from the cover, then handle it according to its instructions. Clean it and let it dry before storage if it is removable. Avoid tipping its dirty water into the pool.
In the pool, remove large debris with a net, brush the walls and waterline using tools suited to the lining, then clean the floor. Skimmer baskets and the pump strainer also need checking. Take the opportunity to inspect seals, coping and visible components.
Reassemble and check the filtration system
Before working on the filter or pump, disconnect the power and follow the manufacturer’s pressure release instructions. Check connections, seals and reinstalled parts. Cleaning depends on the filter: cartridges, filter bags and sand media are not maintained in the same way.
Restore the required water level, valve configuration and priming according to the manual. A pump must not run dry. On restarting, watch for leaks, unusual noises, circulation and pressure. If priming fails or a fault appears, stop the installation and have the cause identified.
Analyse the water before adjusting treatment
Clear water alone does not confirm that the pool is ready. Measure pH and disinfectant, then parameters relevant to your treatment, such as alkalinity, hardness, stabiliser or salt. Compare the results with the recommendations for the system and products used.
Then adjust the parameters in the recommended order. Shock treatment may be useful depending on the water’s condition, but the product, dose and waiting time before swimming depend on the situation. Do not add several corrective products in succession at random, and never mix concentrated products.
Confirm readiness before the first swims
After the initial adjustments, let filtration work and check the water again. Make sure the pool floor is clearly visible, measurements meet the requirements and the waiting periods stated on product labels have been respected. The safety cover and access points also deserve checking.
Record settings and results: they will provide a reference for maintenance during the season. Some water replacement may be necessary depending on the analysis, but completely draining the pool should not be improvised. For disposal of pool water or filter water, check your municipality’s and canton’s requirements.
Help with reopening in French-speaking Switzerland
Piscines Privées can help you prepare for reopening and examine points that require attention. Discover our maintenance service and water analysis.
Send us your municipality, the type of winterisation used and a photo of the plant room on WhatsApp. This will help us prepare an initial discussion suited to your pool.
Sources and technical guidance
Design and maintenance work must be adapted to the pool and equipment. Project documents and manufacturers’ manuals remain the reference.