How to Winterize an In-Ground Pool

Winter is coming and, unfortunately, it’s about that time to close the pool for the off-season. We have put together some easy-to-follow steps that show you how to winterize an in-ground pool. Proper winter closing will keep your pool safe and clean; and will save you time and money when opening your pool next season.
pool magic + phosfree
Eliminate Phosphates & Organic Contaminants
One week prior to closing your pool apply 14 oz. of poolmagic+PHOSfree for every 10,00 gallons of water directly into your skimmer.
pool blaster pool vacuum
Clean your Pool’s Surface
Brush or vacuum your pool until free and clear of dirt and debris. Make sure to scrub the pool walls and floors with a brush to remove contaminants attached to your pool’s surface.
stain and rust remover
Prevent Stain and Scale
To prevent staining an scaling add Stain and Rust Remover. Pour 15oz. of Stain and Rust Remover per 15,000 gallons around the perimeter of your pool.
alkalinity increaser
Balance Alkalinty Levels
Obtain a good test kit ( we recommend the TF 100) and test your Alkalnity levels, adjusting them as necessary. The total Alkalinity for vinyl pools should be in the 120-140 ppm range or 80-120 ppm for plaster. In the case of low Alkalinity levels, add Alkalinity Increaser at the rate of 1-1/2 lbs. per 10,000 gallons.
ph increaser
Balance pH Levels
Test and balance your pH levels. Proper pH levels should be 7.4 and 7.6 ppm. To adjust your pH, use pH Increaser to increase your pH or pH Reducer to lower pH levels.
water hardness increaser
Balance CH Levels
Test and adjust your Calcium Hardness levels to 200-350 ppm. In the case of low Water Hardness levels, add Water Hardness Increaser. If your Water Hardness levels are too high you will have to replace your water to lower Calcium Hardness levels.
Prevent Algae
Add an algaecide to protect your pool during the winter months and prevent the potential for algae blooms. Mix Algaecide with water in a large bucket and pour around the perimeter in your pool. Wait at least one hour before applying any pool shock.
cal-hypo pool shock
Shock your Pool
Shock your pool to free up chlorine and increase the effectiveness during the off-season. The type of shock you use will effect the dosage required, but you will want to bring chlorine levels to 4.0-5.0 ppm. To find out more information on different types of shock and their effects, check out our article here. After distributing chemicals, complete at least one pump cycle to circulate.
pool antifreeze
Prevent Freeze Expansion
Lower waterline below all skimmers and return lines and blow out return lines and skimmer using a shop vac or air compressor. After, remove all drain plugs on pump, filter, and heater. Drain any booster pumps or automatic chlorinators if you have them. Turn off the main power supply and apply winterizing plugs into the return and skimmer lines. After plugs are secure, apply Swimming Pool Antifreeze to all lines ( 1 gallon per 10ft. of plumbing) to prevent freeze expansion in plumbing.
skimmer plug
Protect your Pool’s Plumbing
Place a Skim Insure into the skimmer to seal the skimmer and protect your lines against any ice-pressure that may accumulate in the winter.
pool winter cover
Cover your Pool
Protect the quality of your water with a safety or winter cover. This will protect your pool against harmful contaminants and sunlight which cause a breading ground for algae. For added security with small children, pets and loved ones, use a safety cover (instead) to prevent accidental intrusion.
Previous articleDi-Chlor vs Cal-Hypo
Next articlePool Heater vs Heat Pump
When Kevin’s not enjoying the water himself he’s engaging himself in the wide world of pool and spa knowledge which he passes on to our customers through producing content for our blogs and website. Outside of the pool world you can find him enjoying life with friends, family and his off the wall dog Brixton.