Pool winterizing: how to close it properly for winter
Winterizing your pool (closing it for winter) involves: cleaning the pool thoroughly, applying a shock treatment + algaecide + winterizer product, lowering the water level below the skimmers, draining the pipes to prevent freezing, and fitting a winter cover. Done well, in spring all it takes is shock chlorine and 24 h of filtration to get the pool ready — no green water, no sediment.
Paso a paso
- 1
Clean the pool thoroughly
Brush the walls and vacuum to remove all the sediment. Clean the waterline with a specific descaler if there’s a limescale mark.
- 2
Shock chlorine + long-lasting algaecide
Shock chlorine (15–20 g/m³) + concentrated long-lasting algaecide (500 ml per 25 m³). Filter for 12 h.
- 3
Apply the winterizer product
Specific winterizer product (1 L per 25 m³). This product prevents algae from developing over months without swimming and without chlorine renewal.
- 4
Lower the water level
Drain to 10 cm below the skimmers so ice doesn’t crack the skimmer body if there’s frost (important in cold areas; in Valencia it’s not critical but still advisable).
- 5
Drain the pipes
Drain the suction and return lines. On pools with an outdoor filter unit, empty the pump and filter. On a multiport valve, leave it in the “closed” position.
- 6
Fit a winter cover
An opaque cover (blocks light from reaching the water), properly tensioned and secured. A mediocre cover = a troublesome spring.
Productos recomendados
Los mismos que te llevarías de nuestra tienda física en La Cañada (Paterna).
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When should I winterize the pool in Valencia?▾
When the water temperature drops steadily below 15 °C — usually November. Below that temperature algae don’t develop and the chlorine is consumed much more slowly.
Is it mandatory to lower the water level?▾
In Valencia (frost is rare in outdoor pools) it’s not mandatory to lower it that much, but it is advisable to lower it 5–10 cm below the skimmer so the cover sits correctly and rainwater doesn’t overflow.
Can I skip the winterizer and add more chlorine instead?▾
Technically yes, but chlorine breaks down within weeks and you’ll leave the pool unprotected for months. A winterizer protects the water for months with one dose (Ecoiver Plus, about 90 days); if the pool stays closed longer, follow the reapplication instructions on the pack.
Sigue leyendo
Spring pool start-up: step by step
Remove the cover, top up the level, shock chlorine, algaecide, flocculant, adjust the pH and filter for 24 h. Ready in 48 h.
Green pool water? How to clear it up in 24–48 hours
Green water = algae. Shock chlorine + algaecide + flocculant, in the right order. Results in 24–48 h.