In Ontario, timing your pool opening correctly can save you money, prevent damage, and make pool season more enjoyable. Opening too early or too late can both create problems, so finding the right balance is key.
Watch the Temperature, Not the Calendar
The best time to open your pool is when daytime temperatures are consistently above 10-12C and overnight freezing is mostly over. This usually falls between late April and mid-May depending on the year and your location in Ontario. Opening before freezing temperatures are done can risk damage to your plumbing and equipment if water inside the system freezes.
Don’t Wait Too Long
Waiting to long to open your pool can lead to:
Green water and algae growth
Stronger chemical use to clean it up
Stained liners
More work and higher costs
Once the water warms up, algae grows fast. Opening earlier helps keep your water clearer and easier to balance.
Consider Your Pool Cover
If you have a solid cover, you can usually wait a bit longer because it blocks sunlight and debris. Mesh covers let more light and dirt through, which can cause algae to grow sooner.
For us Ontarians, the best time to open your pool is once the freezing nights are done and the temperatures are staying nice and mild. Open at the right time, and you’ll protect your pool, your gear, and your wallet - and get in the water sooner without headaches.