by Rob Cox, September 27, 2010
10 Steps - How to Winterize an In Ground Pool
For those of us living in the snowbelt, it seems that another season has slipped by. Temperatures this weekend are approaching 32 degrees in some parts of the country, and unless your pool pump is running all night long, freeze damage will result. Pipes, heaters, filters, pumps - all made from strong materials, but all will crack from the expansion of ice within, unless proper precautions are taken.
This article will show you how to winterize your inground pool. All pools are slightly different in their configuration, so use these tips with caution. If you have specific questions on your specific pool and the closing process, send me an email, and pictures if needed, and we can make sure that you are well protected from winter's worst.
1. Balance your pool water. Adjust your pH, Total Alkalinity and Calcium Hardness levels in the pool. It's best to do this several days to a week prior to your pool closing, to make sure that further adjustment is not needed. Shocking the pool with granular chlorine is a good idea before closing the pool, but this also should be done 1 week prior to closing, to allow the chlorine level to drop before putting your pool cover on the pool. High chlorine levels can weaken your winter pool cover, so be careful not to allow highly chlorinated pool water to contact your winter pool cover.
2. Clean the pool very thoroughly. The cleaner the pool is when you close it, the better it will look next spring. Any debris or algae left in the pool during closing will dilute the strength of our winterizing pool chemicals, as these chemicals work on organic matter left in the pool, there is less available for prevention of algae growth during the winter.
3. Lower the pool water. For mesh safety covers, this level should be 8-12" below the tile. For solid pool covers, the type that float on the surface and are held in place with water bags, lower the pool water level 3-5" below the tile. If you have an in ground vinyl liner, you can also make use of a product called an Aquador, which is like tupperware for your skimmer. Snap this on the front of the skimmer and you don't need to lower the water level at all.
4. Add your winter pool chemicals. Many pool owners use a pool closing kit, which usually contains algaecide, borate floaters, stain & scale and some non-chlorine shock. Follow the instructions on the package. These instructions usually recommend adding the chemicals before lowering the pool water, however I prefer to add them after lowering the water level, so the concentration is stronger. Broadcast the chemicals broadly over the pool surface, and use your pool brush to help distribute. If you have a mesh safety cover, we recommend using a pool enzyme product to help control algae growth during the winter. Also helpful is to check the water chemistry during mid spring, about a month before opening, and add another quart of algaecide or refill the floating chemical dispenser.
5. Clean the pool filter thoroughly. For DE filters, remove the assembly from the filter tank and hose very clean to remove all DE powder. DE powder left to dry on the grids during the winter can cause clogging of the fabric, creating filtration problems next spring. If you have a cartridge filter, the same rule applies, remove the cartridge and hose very thoroughly. After blowing the lines, place your grid assembly or filter cartridge back in the tank for safekeeping during the winter. Make sure that you secure the filter lid and clamp band very securely before and after blowing lines. Loose or improperly secured filter clamp bands can cause the filter lid to blow off during start-up, with disastrous or fatal results.
6. Remove drain plugs from pump(s), filter, heater, chlorinators. Look over all the pipes and every piece of equipment, looking for and removing any drain plugs. Open all directional valves to allow water level to fall to the level of the water in the pool.
7. Blow the lines out with air. This is the most important step in the process. Blowing out the equipment and plumbing ensures that there is no water left that can cause freeze damage. If you choose not to blow out the lines, make sure that all of the equipment is completely drained, and that you add non-toxic pool antifreeze the plumbing lines.
You can blow out the lines using a Mighty Vac, as we have described before in a video on how to blow pool lines using a Mighty Vac, you can use a powerful shop vac, or you can use a small air compressor. See our video blog on how to use an air compressor to blow out your lines, by connecting the air compressor hose into the threaded drain plug hole on the pool pump, and using the valves to direct the air. First you direct the air backwards, through the suction lines, to blow out the skimmer lines. Once these lines are plugged, direct the air through the pump (removing the volute drain plug) - through the filter, heater, chlorinator - and finally back to the pool return lines.
8. Plug the lines. Use freeze plugs, or expansion plugs to plug skimmers, returns, cleaner lines. Make sure you plug them all!.
9. Add skimmer bottles. You can use a Gizzmo, which is a combination skimmer plug and ice absorption device. If you are plugging the skimmers with rubber freeze plugs, then use a 1 qt or 1 gallon bottle, empty except for a few inches of either antifreeze or small pebbles. This will weigh the bottle down and allow it to float partially submerged. When the water rises in the skimmer and freezes, the expansion of the ice will collapse the bottle and not the outside walls of your skimmer.
10. Shut off power to the pump, by turning off the circuit breaker. It's also a good idea to remove any timer dogs on the timeclock, just in case someone turns the breaker back on during the winter.
That's about it - as mentioned earlier, every pool is a llittle different - just make sure that all of the water is removed from the plumbing (with the exception of the main drain, which sometimes won't blow out) and from the equipment. Don't cover the equipment with plastic, this can trap moisture and create rust. Heater covers are a good idea however. If you have any questions on winterizing your swimming pool, click the link at the top of the page and send me an email. You can do this!
If you would like to Guest Post on our Pool Blog ~ or for permission to repost our Pool Blog on
your website, please contact the author by the email link at the top of the page. Thank you!