Best practices for ensuring your above ground pool is protected against the brutal Canadian winter.
This guide applies to above ground pool closings for standard, flat sheet winter covers. For anyone planning on closing using an Eliminator Pool cover, please refer to our separate guide on how to do so as some processes will change.
Closing your own above ground pool for the first time can be a daunting task, especially in harsh, northern climates such as Canada. In Ontario, we experience constant precipitation and freeze-thaw cycles that last from late fall to late spring. Many online guides do not properly address all the best practices required to protect your pool. What works in warmer climates will not work in Canada, and can lead to winter damage.
On that note, let's explore the proper way to close and above ground pool in Canada!
#1 - Cleaning Debris in the Pool
Cleaning the pool is the first step in the closing process. We recommend cleaning the pool prior to applying chemicals, in order to ensure that the chemical dissolves properly and does not get trapped in any leaves or debris on the floor. Cleaning all debris and leaves on the pool bottom also helps prevent staining that will show in the spring. Below is the order that you will want to follow for optimized results.
Make sure the temperatures outside have dropped to 10° Celsius or below. This typically means closing the pool mid-September and onwards. Closing the pool too early will result in the water going green because the temperature under the cover fosters algae growth.
Remove solar blanket/solar roller if applicable.
Inspect the clarity of the water. If the pool is cloudy, milky, or green prior to closing, this should first be addressed prior to closing. Closing a clear pool will not only make it possible to actually see the bottom of the pool to clean, but make the pool opening in the spring much easier. View our pool clarity FAQs for more information.
Remove your ladder, drop-in steps, or entrance system from the pool prior to cleaning. This way, any debris underneath or inside the ladder/step will not fall back into your clean pool once removed (be careful not to drag the ladder or step against the liner when removing!)
Physically clean the pool by skimming leaves, vacuuming debris on the floor, and brushing the walls, floor, and cove. Ensuring that you skim, brush, and vacuum is important to make sure the pool is as clean as possible. Empty your skimmer basket after cleaning.
#2 - Apply Chemicals
Proper water chemistry is often overlooked during the winterization process, but it is extremely important for the longevity of your pool. Unbalanced water chemistry can drastically reduce the life span of your liner, and damage pool equipment such as your pump, filter media, or heater. Leaving water unbalanced over the winter is not recommended and can void warranties.
Chemical levels must fall within the ranges below:
Calcium Hardness: 100-160ppm
This stage of the closing process will require your pool to have balanced water (as indicated above), and then a winter chemical kit can be added to ensure your levels stay optimal over the long winter months.
Test your pool's water using Aquachek 7-in-1 test strips. If your chemical levels vary drastically from the ranges listed above, take in a water sample to your local pool dealer and have professional analysis done in order to ensure the proper quantity of chemicals is added. Once the chemicals are balanced, you may then add your closing kit.
With the pump running, you will now apply the pool closing kit. Pre-dissolve the chlorine shock in a bucket of warm water and stir until completely mixed. Apply the bucket of diluted shock to the pool directly in front of the jet, and circulate for 15 minutes before moving onto the next step.
Apply the algaecide to the pool by pouring it around the edges of the pool evenly. Let circulate 15 minutes before moving on to the next step.
(Optional) Apply the stain and scale around the outside of the pool's edge similar to the algaecide.
If there are any residual granules of chemical on the bottom of the pool, use your brush to stir them up into suspension so they dissolve properly. If you leave piles of granules on the pool floor it can bleach or damage the liner.
PRO TIP – Most pool closing kits contain shock, algaecide, and stain and scale. This shock and algaecide is identical to your weekly shock and algaecide in many cases. Stain and scale can be useful when dealing with hard water from wells, or excessive leaf debris, but it is not required for the average above ground pool owner. Use your left over stock of shock and algaecide to save money!
#3 - Drain the Pool to Appropriate Level
Proper water level is a key component of a pool closing. Depending on the equipment and cover used, there are technically a few different levels you can lower your water to. For customers that do not have access to city water, and rely on wells, limiting how much water you drain can save you money on the delivery of bulk water. To keep things simple, we will stick to the standard method. In this method, the water level must be lowered until it is just below the bottom of the jet.
Backwash the pool until the water is at the bottom of the skimmer and the pump runs out of prime. The water should be just about low enough that it doesn’t run into the skimmer.
In order to get the water level down below the jet, use a sump pump or siphon to drain the rest. Be very careful not to go any lower than 1" below the jet, so pay close attention to your pump.
#4 - Winterize the Filtration System
Winterizing your filtration system is often the most daunting aspect of a pool closing for the average pool owner. Depending on the layout of your system, a varying degree of equipment may be required. If your pump and filter are close to the pool, a simple shop vac is all that is required. If you have a long run of pipe that runs from your pool to your pump, you will likely need a large compressor.
Remove your skimmer basket and skimmer weir door. Use teflon tape around the threads of the skimmer Gizmo, then thread the bottom of the gizmo into the skimmer hole. Unthread the bottom of the ball valve so the pipe that runs to the pump is open. Close the ball valve handle to isolate the skimmer. The skimmer will now be water tight due to the gizmo and closed ball valve. Apply antifreeze (non toxic, pool or RV anti-freeze only) to the inside of the skimmer until it is about to run out the mouth of the skimmer.
Remove the jet and place the plug in the jet hole. You may need to use a blue "jet tool" to remove the inner lock ring if it is stuck. After the jet has been plugged, unthread the lower half of the ball valve to isolate the jet from the chlorinator, then close the ball valve.
Remove the drain plug from the bottom of your pump, then open the lid. Remove the pump basket and clean it.
Remove the drain cap on the bottom of the filter. Remove the sight glass and pressure gauge from the top of the filter. Move the filter dial to winterize, and let water drain from all components of the filtration system.
Remove the drain plug from the chlorinator (if applicable).
Once the water has drained from the pump and chlorinator, disconnect them using the unions on their outlet, and take them inside for the winter. The filter will drip water from the bottom plug for a few days and requires no additional action.
If you have a heater, disconnect both the inlet and outlet, and using a shop vac or compressor, blow out the water left inside the heater manifold. Leave the heater unions disconnected. If you have a salt system, disconnect both ends and dump out the water. The salt system will come inside for the winter, including the control box (Hayward Salt systems only).
Using your shop vac, blow out the pumps inlet line that runs to the skimmer. If you have long lines to the pool, you may need a shop vac blowing on one end, and a second vacuum sucking the water on the other, or a large compressor. If you can, try to blow out the water downhill to help the water flow out of the pipe easier. Repeat the process from the chlorinator/salt system line to the jet. Place plastic shopping bags with rubber bands over top of all open pipe connections.
Apply your Gizmo skimmer saver into the skimmer hole, using Teflon tape around the threads of the gizmo. You can now fill the skimmer with anti-freeze (non toxic, pool or RV anti-freeze only). Turn the ball valve under the skimmer off and unthread the ball valve union to completely disconnect the line.
Following the steps above will properly ensure that there is no water left in any of your pipes or pool equipment, which will save them from cracking due to ice expansion.
#5 - Apply the Cover
The last step in the pool closing is to fasten your cover on top of the pool. Although there are several different types of covers on the market, the majority of above ground pool owners will be using a flat sheet winter cover, such as the one pictured above.
Apply the cover to the pool. If the cover is new, you will have to place the cover overtop of the pool in the general position you desire, and then run the cable through the eyelets in the cover, in a motion similar to sewing. After the cable runs all the way around the pool to the point where they are touching, run the cable through the winch, and crank until it is tight.
Do not place the cable underneath the skimmer and jet, this can cause them to be ripped out if the cover experiences lots of tension from the weight of the ice. Instead, run the cable overtop of the skimmer and jet, which will keep the cover away from them.
If you have a Trevi pool with LED lights, you can either remove the light caps (highly recommended if you are in a high rain/snow area) or if you have an oversized cover, you can run the cable underneath the light cap if there is enough slack in the cover inside the pool. Tighten the cable by running it through the turnbuckle and tightening as much as you can by hand. Pull all extra cover material into the pool so it can expand as it fills with water and freezes.
The cover should have plenty of slack, so that rain and ice will not pull the cover tight. It is highly recommended to upsize your winter cover. For example, if you have a 15' round pool, you will want to purchase an 18' round winter cover. This will give you plenty of slack. In Canadian winters, water and ice can build up very quickly and pull down on the cover, causing damage if the cover runs out of slack and puts extreme pressure on the pool walls.
BONUS: Drain Cover When Required!!!
Once the pool has been winterized and the cover is on, a pool owner must still perform maintenance to their pool. Over the course of the fall, winter, and spring, rain and snow melt will pool on top of the cover. Whenever the precipitation on top of the cover is liquid, the customer should drain as much water as possible off the cover using a sump pump, or a specialized cover pump that can be purchased through a third-party retailer. Specialized cover pumps will have an automatic float that will drain the water off the cover automatically, without the risk of sucking the pool water from underneath the cover. If you already have a sump pump, place the sump pump inside of a bucket that has been drilled full of holes, then place the bucket on the cover and control the draining of the cover manually. The bucket will prevent the sump pump from draining the pool's water through the cover. If you drain the pool's water through the cover, you will dramatically increase the risk of frost damage, as the water must stay at the appropriate level for the pool's structural integrity. Periodically draining the cover will significantly remove water (and therefore ice later on) from the top of the cover. Removing this weight from the top of the pool will save the pool from any stress or damage caused by the ice. This will reduce the possibility of frost related damage massively. This is a requirement for warranty.
Set up your sump/cover pump, and periodically check the tension on the cover. If you have a sump pump, place the pump inside of a bucket with holes drilled all over it, then place the bucket on top of the cover. This will stop the pump from draining the water in the pool through the cover. If you have a specialized cover pump, this is not required as they have base plate that stop this from happening.
Never allow a significant accumulation of water to build on top of the cover (more than 4"). Pump as needed until the temperatures are cold enough for a solid freeze.
Once the ice has melted in the spring, continue this periodic draining of the cover until you open the pool. It is recommended that you open the pool earlier in the season (mid April to early May) so the pool is up and running before the warmer temperatures foster algae growth under the cover.