How To Prepare a Pool for Winter
As the autumn leaves begin to fall, preparing your swimming pool for the colder months is essential to protect your investment and ensure the best start to the next swim season. Proper winterisation is not just about keeping the water clean; it's a critical process to prevent costly damage from freezing temperatures and aggressive scale build-up.
For owners of in-ground swimming pools and large installations, neglecting this process can lead to serious damage to pumps, filters, and underground pipework, repairs that can be extremely costly. Following this comprehensive guide from Deep End Pools ensures your facility survives the winter unscathed.
Understanding the Importance of Pool Winterisation
Pool winterisation is the process in of chemically preparing your water and physically protecting your equipment to withstand a long period of inactivity. This process allows you to maximise the lifespan of your pool's surface and machinery while reducing energy costs.
Failing to winterise your pool in the UK climate, where freezing is a significant risk, can lead to severe issues:
• Algae Bloom: Excessive growth that requires intensive cleaning and chemical use in spring.
• Corrosion and Scale Damage: Imbalanced water pH can damage the pool finish and internal components of the heater or pump.
• Freezing Damage: Water expands when frozen, cracking pipes, skimmers, and heat exchangers. This is the single biggest threat to in-ground pool infrastructure.H2 : Step-by-Step Guide to Winterising Your In-Ground Pool
A successful pool closing relies on precision and detail. Here is the comprehensive process:
1. Thoroughly Clean and Balance the Water
Begin by conducting a final, thorough clean. Skim the surface for leaves and debris, and then brush the walls and floor aggressively to dislodge any lurking algae spores or settled dirt. Vacuum all surfaces, paying special attention to corners and steps where water circulation is low.
Once clean, test and balance your water chemistry. Accurate levels are vital to protect your pool’s interior finish and colour from scale and staining over winter:
• pH: 7.2 to 7.6
• Total Alkalinity: 80 to 120 ppm
2. Add Essential Winter Chemicals
After balancing the water, introduce your specific winterisation chemicals:
• Algaecide: A long-life, non-foaming winter algaecide is essential to stop algae growth while the filter is off. Use the dosage specified for your pool volume.
• Sequestrant/Stain Inhibitor: Use a metal sequestrant, especially if you top up with well water or if you are in a hard water area. This prevents metals from staining your pool surfaces.
• Winter Pill/Enzymes (Optional but Recommended): A slow-release winter pill is a convenient way to keep the water sanitised and clear throughout the cold season, reducing the workload come spring.
3. Shock the Pool and Circulate
For the final step in water treatment, shock the water using a high-strength chlorine or non-chlorine shock. Allow the pool pump to run overnight (or for a full circulation cycle) to ensure the shock and chemicals are fully mixed and distributed throughout the system.
4. Lower the Water Level and Clear Plumbing Lines
This step is critical for preventing freeze damage in all in-ground pools:
• Lowering Water: Carefully reduce the water level to below the skimmer mouth and all return fittings. This prevents water from freezing in the skimmer housing and cracking it.
• Blowing Out the Lines: This is the most important anti-freezing measure. Using a powerful air compressor or blower, force all water out of the pipes, filters, heater, and pump. Once clear, plug the return lines and skimmers using specialised Gizzmos or rubber expansion plugs.
• Adding Pool Antifreeze: For an added layer of protection, especially in external plant rooms, introduce propylene glycol pool antifreeze into the plumbing lines after they have been blown clear.
5. Clean, Drain, and Protect Equipment
• Filter Cleaning: Remove and thoroughly clean your filter elements or backwash your sand filter. Open all drain plugs on the pump, filter, and heater to ensure all water is removed.
• Protecting Pumps and Heaters: Disconnect and store any equipment that could be damaged by moisture or freezing, such as electronic controls. Cover the main pump and motor unit with a weatherproof bag or box, or preferably remove it and store it indoors.
• Remove Accessories: Take out and dry all accessories like ladders, diving boards, and rails, storing them away safely. This is especially important for saltwater pools, as high salt levels accelerate corrosion.
Essential Protection for the Coldest Months
Once your pool is winterised, protecting it through the months of deepest cold and potential freezing is critical to structural integrity:
1. Using a Robust Pool Cover
Cover your pool with a secure, solid winter cover or safety cover. A solid cover prevents sunlight from entering (which inhibits algae growth) and stops heavy debris from contaminating the water. Ensure the cover is properly tensioned to handle snow and heavy rainfall.
2. Deploy Ice Equalisers
For large in-ground pools, freezing ice can exert enormous lateral pressure on the pool walls, especially on the tile bands or edges. Deploying ice equalisers or weighted plastic water bags is a vital preventative measure. These float on the surface, absorb the pressure of the expanding ice, and protect the pool structure from cracking or deformation.
3. Continuous Monitoring
Even when closed, a pool requires occasional monitoring:
• Cover Check: Regularly clear debris, standing water, or snow from the cover to prevent the cover itself from being damaged or sinking.
• Equipment Check: After severe weather, check the plant room to ensure no connections have loosened and no water has inadvertently entered the system.
• Chemical Top-up: If your winterisation period is longer than six months, consider opening the cover on a mild day to check the water clarity and potentially add a small top-up of liquid algaecide to ensure the water stays healthy.
By following this comprehensive winterisation guide, your pool will be protected from the harsh UK winter, ensuring you are ready for a quick, efficient, and hassle-free opening when the warmer weather returns.
Contact Deep End Pools today for professional winterisation services.
