Pool Skimmer Winterizing and Antifreeze

pool-skimmer-winterizingWinterizing a pool skimmer is a topic worthy of discussion this time of year. Fail to winterize the skimmer properly and you face cracked skimmers and broken pipes come spring.

Pool antifreeze – is it needed? When should you use pool antifreeze in the skimmer, and when is it not necessary, except for extra peace of mind?

Inground Pool Skimmer Winterization

To winterize a skimmer, in a nutshell, is to remove all of the water from the skimmer body, and the skimmer pipe. Then, you need to plug the pipe or otherwise keep the water from getting back into the skimmer pipe. Finally, you’ll need to have some protection from rain water or pool water that will get into the skimmer well; freeze, expand and crack the skimmer.

Drain the Skimmer: The first step must be to lower the water level in the pool below the skimmer. If you have a separate main drain line, and a sand or DE filter, you can close off or plug the skimmer, and set your filter valve to backwash, waste or drain.

Let the pump lower the water at least an inch below the skimmer opening, then slowly open the skimmer valve to suck all, or most, of the water out of the pipe. If you have more than one skimmer, do each one separately, and you can pull most of the water out of the line.

With the addition of some pool antifreeze (see below), this may be a suitable skimmer winterization for a pool in growing zones 7-10. Northern pools should blow the lines out with air. See my earlier blog post Inground Pool Winterizing Procedures for more information on how to blow out or winterize skimmer pipes.

winterizing-a-skimmerPlug the Skimmer: The second step in winterizing a skimmer, after the skimmer pipe has been emptied or blown of water is to plug the pipe so that water can’t get back into the pipe, from the pool, or from precipitation during winter.

You can use threaded plugs with o-ring, rubber expansion plugs of size #9 – #11, or a Gizmo can be used to winterize the skimmer. For threaded plugs, the o-ring is important, and using Teflon tape on the threads adds another layer of security. Make sure that rubber plugs have a good, tight fit.

aquador-skimmer-closureVinyl pools with Hayward skimmers can use the snap-on skimmer closure from¬†Aquador. It’s snaps over the skimmer, like a lid for a food container. It requires that you replace the current skimmer faceplate with the Aquador faceplate, but once that’s done, skimmer winterization is a snap every season!

skimmer-plug-winterizingNew on the market for winterizing inground and above ground vinyl pool skimmers is the Skimmer Plug, which seals up against the inside of your existing skimmer faceplate for a water tight winter skimmer plug. No need to replace the current faceplate, these are made to fit the inner dimensions. Brilliant!

Protect the Skimmer: After draining and plugging the skimmer, the final and often neglected step must be done. If pool water overflows into the skimmer, or as it slowly fills with rain and snow melt, the water inside of the skimmer, on top of the plug, may freeze during winter.

Water inside the skimmer well that freezes puts extreme outward pressure on the skimmer walls as it expands. To break up the ice sheet and protect the skimmer, use one of these three methods.

  1. Fill a quart or gallon jug 1/3 full of pool antifreeze, and drop in skimmer, or…
  2. Use a Skimmer Guard or Gizmo type of skimmer plug, or…
  3. Add pool antifreeze to the skimmer, on top of the plug.

tip-skimmer-winterizingTo keep rain water out of the skimmer, use squares of plastic film placed between the skimmer lid and frame, and screw down the skimmer lid to sandwich the plastic tightly.

Pool Antifreeze

pool-antifreezeWhen should non-toxic pool antifreeze be used? Whenever there is doubt that all of the water has been blown or drained from the pool pipes.

If enough is pool antifreeze is used, you could avoid blowing the lines all together. Each gallon will treat 10 feet of pool pipe.

Pool antifreeze is also used for winterizing a pool skimmer, as mentioned above, to keep water from freezing inside of the skimmer well, and cracking the skimmer.

skimmer-winterization-with-pool-antifreezeMake sure to only use product labeled non-toxic Pool Antifreeze. Automotive antifreeze is toxic. Ethylene Glycol should never be used in winterizing a skimmer or pool.


funnel-hose-pool-antifreezeTo winterize a skimmer, just pour pool antifreeze into the skimmer. For other pipes, you can introduce the antifreeze with a funnel and hose set-up.


Don’t pour pool antifreeze into your pool equipment – pump, filter, heater.¬† It can damage sensitive pool parts. And never add antifreeze to a chlorinator, a reaction could occur.

Well, that’s about all I know about winterizing pool skimmers. I hope this was helpful and informative. If you have questions about skimmer winterization, leave a comment below or call our helpful pool winterization specialists!

Davy Merino
InTheSwim Blog Editor



Pool Skimmer Winterizing and Antifreeze — 3 Comments

  1. Pingback: What Happens If I Don’t Close My Pool? | InTheSwim Pool Blog

  2. Pingback: FilterBalls – Do They Really Work? | InTheSwim Pool Blog

  3. Pingback: Sunbelt Pool Closing for Off-Season Pools | InTheSwim Swimming Pool Blog

Leave a Reply

Your email address will not be published. Required fields are marked *