How to open your pool after winter

When is the right time

Open the pool when the water temperature starts to rise steadily, usually once it goes above about 15 °C. In Attica and on the islands that happens somewhere between April and May. Don't wait for the first heatwave: algae grow fast in warm water, and if the pool is still closed, the first clean-up becomes much harder work.

Opening a few weeks before the first swim gives you time to fix whatever you find at your own pace, from a worn O-ring to stubborn cloudiness.

The steps in order

1. Clean the cover before removing it. Clear leaves and rainwater off the top so they don't fall into the pool. Rinse it, let it dry and store it folded in a shady spot.
2. Remove the winter floats and plugs from the skimmers and return inlets, and put the baskets back.
3. Raise the water level to about the middle of the skimmer opening or, in an overflow pool, to the normal level in the balance tank.
4. Get the plant room ready. Make sure it is dry and that the electrical panel is working normally. Put the drain plugs back in the pump and filter, check gaskets and O-rings, open the valves, and fill the pump strainer with water before starting it.
5. Start circulation and look for leaks, unusual noises and the reading on the pressure gauge.
6. Clean the filter. A backwash followed by a rinse removes whatever built up inside it over the winter.
7. Brush and vacuum the walls, steps and floor.

Water chemistry

After a few hours of circulation, take a sample from elbow depth, away from the return inlets, and test the water. Make corrections in order:

• first total alkalinity, which stabilizes the pH,
• then the pH, to 7.2–7.6,
• chlorine last.

Water that has sat all winter almost always needs a shock chlorination to neutralize the organic matter that has built up. Add the chlorine dissolved or through a dispenser, never as granules directly onto the liner. Let the filtration run continuously for one to two days, and backwash the filter again if the pressure rises.

If you found the water green under the cover, first follow the steps for green water and then continue with balancing.

Checks worth doing now

• The liner: stains, wrinkles or small holes, mainly at the waterline and on the steps.
• The water level over the next few days: if it drops more than evaporation explains, look for a leak.
• Lighting, timer and heating, if you have them, so you don't discover a fault mid-season.
• Ladders and handrails: tighten the screws and clean them.
• The summer cover: tears and worn bubbles.

The more careful the winterizing was, the quicker the opening. Clean water and correct chemistry in the autumn almost always mean clear water in the spring.

Don't swim until the water is clear and free chlorine is back to 1–3 mg/l after the shock.

Questions

See also