In London and Stratford, the first hint of spring means one thing: pool season is just around the corner. But after a long Southwestern Ontario winter, you can’t just pull off the cover and dive in.
Opening your pool correctly is the difference between a crystal-clear oasis and a “green monster” that costs hundreds in extra chemicals. At Custom LeisureScapes, we’ve put together the ultimate 2026 spring opening guide to help you get it right the first time.
The “sweet spot” for opening your pool in Ontario is when daytime temperatures consistently stay above 15°C (60°F).
The Early Bird Advantage: Opening in late April or early May—before the weather gets truly hot—prevents algae from blooming under your cover.
The “Victoria Day” Rule: While many wait for the “May 2-4” weekend, opening 2–3 weeks earlier gives you a head start on balancing your water chemistry so it’s actually ready for swimming by the holiday.
Before you touch the water, do a walk-around of your backyard:
Check the Deck: Look for any shifting or cracks in your concrete or stone caused by winter frost.
Safety First: Test your gate. Under the 2026 Ontario safety regulations, all pool gates must be self-closing and self-latching. Ensure the latch is at least 1.22 metres (48 inches) above the ground and working perfectly.
Inspect the Cover: Remove any standing water and debris from your winter cover using a submersible pump and a soft brush.
Now it’s time to bring the “heart” of your pool back to life:
Remove Winter Plugs: Swap out your winterizing plugs for your regular return jets and skimmer baskets.
Reinstall Accessories: Put your ladders, diving boards, and lights back in place. Pro Tip: Lubricate the bolts now to prevent rusting over the summer.
Prime the Pump: Fill the pump basket with water, ensure all drain plugs are tight, and turn it on. Watch the pressure gauge—if it spikes or drops, you may have a blockage or a leak.
Top It Off: Use a garden hose to bring the water level back up to the middle of the skimmer opening.
Clean the Filter: Whether you have a sand or cartridge filter, start the season with a clean slate. Backwash your sand filter or give your cartridges a deep soak.
Run the System: Keep your pump running for at least 24 hours before you start testing the water. This ensures the old and new water are fully mixed.
Don’t guess—test. Bring a sample to Custom LeisureScapes or use a high-quality home kit.
Balance First: Adjust your Total Alkalinity (target 80–120 ppm) and pH (target 7.2–7.6) before adding other chemicals.
Shock Treatment: Give the pool a “triple dose” of chlorine shock to kill off any dormant bacteria or algae spores.
Algaecide: Add a preventative dose of algaecide to keep the water clear as the sun gets stronger.
If you pull back the cover and see a swamp, don’t panic. It usually means the cover wasn’t perfectly sealed or you waited a bit too long to open.
Remove Debris: Scoop out as much organic matter as possible so the chlorine can focus on the algae.
Vacuum to Waste: If you have a bypass valve, vacuum the sediment directly out of the pool rather than through the filter.
Continuous Filtration: Run your pump 24/7 until the water is blue and clear.
Too busy to spend your Saturday scrubbing the liner? Custom LeisureScapes offers professional opening services across London, Stratford, and the surrounding counties. We’ll handle the heavy lifting, equipment startup, and initial chemical balancing so you can just enjoy the view.
Ready to start the season? Contact Custom LeisureScapes today to book your spring opening!
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