Winterizing Your Pool Without Losing Your Mind
You pull the cover off in October, the water looks fine, and then you remember you have to close the pool for winter. Most people buy a generic closing kit at the big box store and treat the instructions like suggestions. That is how you end up with cracked pipes and a green slush bucket in spring. The instructions that come in the kit are usually two pages of vague bullet points written by someone who has never actually dealt with a real-world plumbing setup. Pool Closing Kit Instructions typically tell you to balance the water, blow out the lines, add antifreeze, and drop an ice compensator in the skimmer. That is the skeleton of it. The reality is in the details most people skip because they sound technical and intimidating. Here is what actually matters. Start with the chemistry before you do anything else. Test your water and get the levels right. pH between 7.2 and 7.6, alkalinity around 80 to 120 ppm, and calcium hardness ideally in the 200 to 400 range. People rush this part because it feels like waiting, but winterizing into unbalanced water is like going to bed hungry and then complaining about the dream. The minerals will eat your plaster and the lines if the chemistry is off. I learned that the hard way in 2019 on a client's gunite pool. We closed it at pH 8.0 because the owner was in a hurry. By March, the return jet faces were pitted and flaking. Cost us three hours of grinding and a repaint job that could have been avoided with thirty minutes and a $15 test kit.
Shock the water with a non-chlorine shock or a standard chlorine shock at closing dosage, whichever your kit includes. Let the filter run for six hours minimum after dosing. While that is running, you need to prepare the plumbing. This is where people mess up. Turn off your heater and set the pump timer to off. Remove the pump, drain it completely, and store it indoors if possible. Leave the multiport valve in the summer position and remove the plug or drain the valve body so water does not sit in there and freeze. For the skimmer and return lines, you are going to blow them out with an air compressor. Do not use the leaf guard that fits in the skimmer throat during blowout. It restricts airflow and leaves water trapped above the line. Pull it out, plug the skimmer opening with a winterizing plug or the included face plate, and then blow the lines from the skimmer side first, then the return side. Here is a practical problem I deal with regularly that the instructions never mention. Some pools have multiple return jets on different zones, and one line will clear while the others still have water. What happens is the compressor pushes air through the path of least resistance and the other lines stay wet. My workaround is straightforward. Close the valve to the line you just cleared, or if you do not have individual zone valves, temporarily cap the clear return with a blank plate and keep working the others. It adds maybe twenty minutes to the process and saves you from cracking a pipe in January.
Once the lines are blown out, add antifreeze to each line. Use pool-grade non-toxic antifreeze, not automotive stuff. Put about two to three gallons per line depending on line length. You want to see liquid come out of each return jet after filling the skimmer with antifreeze too. That confirms the line is full and water has been displaced. Drop your ice compensator device into the skimmer. These are the little plastic gadgets that swell as water freezes and prevent the skimmer face plate from being crushed. They work reasonably well in moderate climates. In areas where temperatures drop below twenty degrees Fahrenheit regularly, I usually recommend a second backup measure like stuffing a closed cell foam insulation tube around the skimmer throat or using an inflated baggie trick I picked up from an old contractor. It is not glamorous but it works. Cover the pool. Make sure the cover is clean and free of debris before you lay it down. Use a cover pump or have a plan to remove standing water and snow. Water sitting on a winter cover adds enormous weight and is the fastest way to sag a cover until it collapses. I have seen covers hold six inches of rainwater and then give way at three AM, dumping a leaf net full of debris into the pool. Check the weather forecast and move proactively. Some closing kits include test strips for spring opening too. Keep them handy. When you pull the cover in spring, test the water again before you start the pump. If the chemistry is way off, do not just turn the pump on and expect everything to normalize. Balance the water first. Running the filter through unbalanced winter water just circulates whatever happened in those six months.
Get the Full Details
One thing the instructions never warn you about and should. If you have an automatic chlorinator or salt cell, you need to remove and drain it or shut it down properly. Leaving a salt cell full of water over winter will crack the cell housing. Same goes for any inline chemical feeders. Take them apart, drain them, and store them inside. It takes ten minutes and replaces a part that runs two hundred dollars. The whole process for an average residential pool with a standard closing kit takes about ninety minutes to two hours if you are methodical. If you are winging it and figuring things out as you go, it can stretch to three or four. Budget accordingly. Get the right tools before you start. A good air compressor with a regulator, the plugs and caps from the kit, a shop vac or cover pump ready for spring, and a basic water test kit. Everything else is just follow-through.
