Ontario’s winters test every backyard pool. When water freezes it expands, which can put pressure on plumbing lines, coping, and even the strongest fiberglass swimming pool.
At Okeanos Pools GTA, we’re here to help you follow the right winterization process, so that you can prevent damage, reduce the risk of algae growth in the spring, and keep your investment in the best condition for the next season.
Why a Fiberglass Swimming Pool is the Best Pool Choice for Ontario
Fiberglass pools are well suited for Ontario’s climate. At Okeanos Pools GTA, our designs, materials, and installation process make these pools reliable for homeowners who need a swimming pool that can handle cold temperatures and seasonal shifts.
Freeze-Thaw Friendly
Our fiberglass pools have a flexible ready to install shell that can adjust slightly to winter temperatures. This helps prevent structural damage that might happen to more rigid materials when pool water turns to ice and expands.
Non-Porous Gelcoat
The gelcoat surface resists algae growth because it’s non-porous. That means fewer chemicals are needed to maintain clean pool water, and many homeowners see noticeable cost savings on seasonal pool cover treatments and pool maintenance.
Lower Lifetime Cost
A fiberglass swimming pool avoids the resurfacing or liner replacement costs that inground pool owners with concrete or vinyl often face every decade. Properly winterizing also prevents cracked or damaged equipment that can lead to costly repairs.
Energy Efficient
Fiberglass shells help reduce filter running time in cooler months. The light-coloured finishes reflect solar heat, and the insulated structure helps maintain pool water temperature, creating a little cost savings in reduced use of support equipment.
Speedy Installation
Most of our fiberglass projects move from excavation to swim-ready in less than two weeks. With our premade shells that are installation ready, you’ll have reduced use of heavy machinery and fewer delays,so you can appreciate a faster build with little disruption.
These advantages make fiberglass the top choice for Ontario homeowners. Winterizing a fiberglass pool is simpler, requires fewer chemicals, and keeps the pool securely protected for the entire winter season. Learn more about our fiberglass pool options at Okeanos Pools GTA.
Pool Equipment, Chemicals & Supplies
Closing your pool for winter requires the right tools and a few pool chemicals. Preparing them in advance makes the process smoother and helps your pool be in top condition come spring. Here’s our some of the tools we recommend having on hand for freezing protection:
- Enzyme-based scale & stain inhibitor
- Phosphate remover (optional but helpful)
- Shop-vac or small air-compressor (20–30 psi)
- 1½ in. rubber expansion plugs or threaded return plugs with O-rings
- Skimmer “Gizzmo” ice compensator
- Propylene-glycol pool antifreeze (never automotive)
- Soft-bristle wall brush and manual vacuum or robotic cleaner
- Winter safety cover or solid tarp plus water-bags
- Cover pump or siphon for melt-water
Step-by-Step Closing Procedure
Each one of the following steps prevents freezing water from damaging pool components and shows how to winterize a fiberglass pool properly.
- Balance water chemistry: Adjust pool pH to 7.2–7.6, total alkalinity to 80–120 ppm, and calcium hardness to 175–225 ppm. Test regularly to ensure stability.
- Shock and circulate: Raise chlorine to 10 ppm, run the filter pump for 24 hours, then let levels drop to 3–5 ppm.
- Add winter chemicals: Use an algaecide for cold water, then apply an enzyme or phosphate remover. Consult chemical manufacturer’s directions before use.
- Deep clean: Use a pool vacuum, brush the walls, empty baskets, and clean the filter so floating debris does not decay under ice.
- Lower the water: Drop the water level just below the skimmer mouth or lowest return jet. Never drain pool completely, as water weight keeps the shell stable.
- Blow out suction line: With multi-port set to recirculate, connect blower to the pump outlet until bubbles appear. Add non toxic antifreeze, insert Gizzmo, and tighten.
- Blow out return lines: Push air through until mist appears. Add antifreeze, insert plugs, and tighten.
- Drain equipment turn: Remove pump plugs, tilt housing, and store equipment indoors if possible. Open filter drain, set valve between positions, and store other pool components warm.
- Remove accessories: Take out ladders, handrails, drop-in lights, and other accessories. Clean and store equipment indoors.
- Cover pool securely: Use a seasonal pool cover or tarp. If solid, add an air pillow and plan to remove standing water with a cover pump.
Special Fiberglass Considerations
Our fiberglass pools from Okeanos Pools GTA benefit from unique features, but require careful practices during the winterization process. You should keep sump pipes clear to drain equipment and turn water away from the shell. We also recommend wiping the gel-coat band below the coping with a non-abrasive cloth and apply a protectant to prevent dulling. Use enzyme treatments to protect tiles and prevent scale during the off season.
Winterizing additional pool features such as spillways or lights should also be done to keep your pool looking good as new.
Off-Season Pool Maintenance
Ontario winters bring both cold temperatures and mid-winter thaws. We strongly advise pool owners to check their pool securely after heavy snowfall or melt. Brush away floating debris, pump water off solid covers before it freezes again, and lift the flap to check water chemistry. If chlorine is low, a small dose of sanitizer will prevent algae growth without restarting the pool pump.
Spring Re-Opening at a Glance
When temperatures begin to reach 10 °C in late April, it’s time to reverse the winterization tasks. Remove the pool cover, raise the water level, reinstall the pool pump and filter pump, and test regularly at a testing facility. Because the pool was closed properly, the swim season starts with less maintenance work, fewer chemicals, and a pool ready for warm weather.
Keep Your Pool Safe in Cold Climates with Okeanos Pools GTA
Proper winterization practices help prevent damage, protect your pool equipment, and keep your fiberglass pool in top shape through the winter months. At Okeanos Pools GTA, we handle assisted pool installation and customization services built on industry standards. Contact us today, and our team of pool professionals will be happy to answer any questions on the winterization process, or to help you get started on your own fiberglass pool.
