With summer coming to an end and fall right around the corner, it's time to start thinking about preparing your pool for the winter months. Some experts agree that seasonal temperatures haven't been so seasonal in recent years, as homeowners have experienced Indian summers and milder winters and closed their pools too soon. This can lead to an increase in the growth of algae and (more importantly) less time for families to enjoy their pool. By following some of these easy and industry-proven tips now, you can save time and money when you open your pool next year.

Whether you have an in-ground pool or an above ground pool, the process is easier than you think. Here are some pool closing tips from some to help you get started. 

In-Ground Pools

What You Will Need:

  • Safety Pool cover
  • Winter plugs for return jets
  • Gizmos* to plug and protect your skimmers
  • Winter closing kit
  • Air compressor/blower
  • Winter pill (recommended by experts to keep the pool water clear all winter)

Clear the Decks

  • Remove your diving board (if you have one), ladders, safety ropes and any other equipment that may be in or around the pool. Do not remove the filtering equipment.
  • Remove eyeball fittings from all return lines and the skimmer baskets from all skimmers. (If you choose to leave the skimmer baskets, you can place all of the plugs and fittings in there so you know where they are next spring.)
  • If you have an automatic cleaner with a dedicated line, be sure to remove the plastic adapter. The return lines should all be large, threaded openings that will fit the same sized rubber plug with a wing nut.

Test and Clean the Water

  • Test the pool water to ensure it is properly balanced. Experts suggest taking a sample to your local pool dealer, if possible, or to use test strips. The pH should be between 7.4 and 7.6 and the alkalinity should fall between 100ppm and 150ppm. You should also make sure the sanitizer is at the correct level. (Note: It's acceptable to keep chemical ranges on the high end when closing your pool, since they will most likely fall during the winter months.)
  • Make sure the pool is clean and free of debris before adding winter chemicals. Skim the surface, and vacuum the pool floor (either with an automatic cleaner or manually) and brush down the walls and steps.


Add Chemicals

  • Now that your pool is clean and balanced, it's time to add the winterizing chemicals.
  • Shock the pool 4-7 days before closing. Then, add the algaecide right before covering the pool. (Adding them together will negate the process, since algaecides are eaten away by the high levels of chlorine from the shock.) Algae is known for going from bad to worse in no time, so treating it before closing the pool will save you time and money in the spring and have you swimming in it sooner. No one likes a green pool – not to mention the fact that it is a breeding ground for mosquitos!
  • Check for metal in the water. Leaving it untreated may result in ugly stains that can be permanent or difficult to remove.
  • Run the pump during and after you add the chemicals to ensure proper distribution throughout the pool. Make sure to clean the filter often during this process to remove algae from the filter. It will put less stress on the pump and make filtering more efficient. (Note: If using a chemical kit, check the directions to see if it's necessary to run the pump. If not, you can add the chemicals from the kit right before putting the cover on.)


Backwash/Clean the Filter and Pump

  • Clean the filter and pump before blowing out the lines.
  • After backwashing the filter, open the pump lid and remove any debris in the basket. Be sure to return the basket when done and securely put the lid back on.
  • Before blowing out the lines, make sure to turn your filter back to "Filter" on your multiport valve.

Blowing Out the Lines

You may want to hire a professional if you are unsure about how to properly blow out the lines. If done incorrectly, you may run the risk of your pipes cracking underground (which can be extremely costly to repair).

  • First, you want to make sure the valves are positioned so that the skimmers and the main drain at the bottom of the pool are open. If your pool does not have a main drain, then you will be working with only one opening.
  • Second, hook the air compressor up to the pump by unscrewing the drain plug located on the pump housing (on the lid). Thread the air compressor into the drain plug opening and start blowing air into the lines until you see bubbles coming from the return lines and the skimmers. (It may be necessary to purchase an adapter for your air compressor if the threading isn't the same.)
  • Allow this to run for two minutes and look to see which line is blowing first. You will see bubbles coming from either the return lines or the skimmers. (For this blog, let's assume that the bubbles are coming from the skimmer.) You'll want to take your gizmo* or rubber plug and plug the hole in the bottom of the skimmer where you see the air coming from. If using a gizmo, thread it into the hole.
  • Next, tightly plug all the return lines that are blowing bubbles with rubber plugs and make sure you don't see any more bubbles coming out. The main drain at the bottom of the pool will be the last to blow, but you won't have to swim to the bottom to plug it. At this point, you can turn off the air compressor.
  • If you have a pool heater, you may want to consider hiring a professional if you're not comfortable with the process. Here is a quick overview of what to do:
  1. Remove drain plugs from the heater.
  2. Turn air compressor back on.
  3. Close off all the valves (except the one to the heater) to redirect all the air into the heater. You should see the water begin to come out of the heater drains. Continue to run the compressor until you do not see any more water.
  4. Replace the drain plugs on the heater and remove the drain plugs from the filter and chlorinator (if you have one).
  5. Turn the air compressor off and remove it from the pump.
  6. Store the drain plugs in the pump housing for safekeeping.

Putting the Cover On

  • Having the proper water levels are extremely important before putting the pool cover on. The water will support the weight of the snow that falls on the cover. If water levels drop below the manufacturer's recommendation, the excess stress on the cover may cause damage and void your warranty. It is suggested to clear snow from the skimmer box often to check the water levels. Add water when levels are low. You can also hire a pool professional to evaluate the levels for you. These are the recommended guidelines:
  1. For mesh pool covers, the water level should be between 15"-18" below the top of the swimming pool.
  2. For solid covers, the water level should be between 12"-16" below the top of the swimming pool.
  • *A gizmo is a long, hollow plastic tube that threads into the skimmer opening to prevent the skimmer from cracking in the cold winter weather. The gizmo is an ice compensator, which means that if water gets into your skimmer and freezes and ice expands, the gizmo will absorb the expansion (instead of the skimmer). This protects the skimmer from cracking. If you are using only a rubber plug and not a gizmo, be sure to put plastic soda bottles in all of your skimmers (with the caps on) to serve as ice compensators.


We hope you found this information on closing your pool for the winter helpful. As summer winds down, let's hope for a few more weeks of great weather so you can enjoy your pool a little longer with family and friends and if you want, kick back, and hire a trained and licensed swimming pool professional to take care of closing your pool.