When preparing an outdoor pool for winter it is important to start with a clean and balanced pool. To prevent broken pipes and or equipment due to expansion from freezing. There are several options.
#1 – Lowering the level of the water in the pool to just below the skimmer to ensure all water has been drained from the lines, pump and heater. This might require blowing the lines out with a shop vac.
#2 – Also a non-toxic antifreeze can be added in some cases. For pools with variable speed pumps and where lowering the pool is not an option, circulation at a reduced GPM at designated intervals during the coldest months will help with a hassle free spring pool startup.
#3 – It is not recommended to completely drain a pool due to hydrostatic pressure from ground water. This hydrostatic pressure can crack the shell or even force the pool out of the ground.
#4 – Heavy rains or snowfall can cause damage to your pool cover. Some pool covers are designed to let water through and some covers do not. Those covers that do not should have a surface cover pump to eliminate damage from standing water. From my experience it is a good idea to have a backup pump as these types of cover surface pumps can fail from time to time. There may be less damage to the pool structure by leaving water in the pool during the off season. Pool covers control staining and keep debris out. Covers are not designed to prevent animals or people from falling into the pool; unauthorized access must be prevented (even vandals).
#6 – In unheated, moist areas, equipment should be lightly sprayed with a water displacement product. Whenever possible remove these items to a warm storage place.
#7 – All outdoor furniture, plumbing, and accessory electrical fixtures should be stored indoors if possible. Pump houses, offices, staff rooms and other indoor areas that may not be heated need a closing procedure as well.
#8 – The operator should compile a master list of all items and where they are stored. Checklists are essential in having an easy startup months later when the pool reopens.
#9 – Even in the off season pool balance should be maintained to prevent damage. Lower winter temperatures will reduce the rate of microorganism growth.
#10 – Finally, secure the pool area.
For checklists and more tips you can refer to your current Pool & Spa Operator™ Handbook from your CPO® certification course.