What is Winterising and why should you do it?

What is Winterising and why should you do it?

What is Winterising your Pool?

Pool Winterising is a term used to describe the process for reducing the chlorination and filtration in your swimming pool over the cooler months when it is not used as frequently.  Winterisation can save energy and therefore you can save money on electricity bills, whilst also ensuring your pool is ready for swimming when the weather turns warm again.


By reducing chlorination and filtration, but not managing water balance, there is the risk of green algae blooms, blackspot and mustard algae.  It is therefore essential that the pool water is balanced throughout winter and not simply forgotten about and allowed to turn green.  Without Winterising the pool water, it can be detrimental to the pool surface and equipment reducing both their life expectancies.


Indeed, many pool owners have the misconception that they can simply switch off their pool equipment in Winter.  In doing, so they are most likely causing an expensive green pool clean-up in Spring, potentially reducing the life of their pool surface, pool blanket and even the equipment.  Pool Equipment that has been left off for months can often seize when started again and potentially need repairing and/or replacing at the beginning of the swimming season.

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How to Winterise your Pool

If you wish to reduce chlorination and filtration you should put a Winter algaecide in the pool to help prevent blackspot, mustard algae and/or the pool turning green.


If you are running your pool all year round, you can reduce filtration time to between 4-6 hours (ie. 3 hours in the morning and 3 hours at night) because of the decrease in temperature and it will not be necessary to add an algaecide, as filtration and chlorination are adequate.

In saying that, adding a preventative algaecide all year round is a good idea as an insurance measure in case something goes wrong with the equipment and it goes unnoticed for a few days.  Because it is wet and cold outside and dark a lot earlier in the Winter months, you may be less likely to go outside to check on the pool.  Therefore, your pool equipment may not have been working for days and your pool has turned a nasty shade of green before anyone notices.  An algaecide will help to prevent this or lessen the severity – which will save you time and money in the long run.

What pool chemicals do I need?


Jim’s Pool Care’s expert technicians can provide you with the right advice on how to properly Winterise your pool.  You will need a copper based algaecide for winterising your pool and our Jim’s Pool Care team can provide you with a Winterise Treatment Pack to ensure that you have everything required to keep your pool in good shape over Winter.

Alternatively, you may decide to leave it to the professionals and Jim’s Pool Care can offer free quotes to come out and Winterise your pool for you. The will adjust your timers, clean filters and add what is required. We recomend all year round pool servicing so think about that option also.


It is important to note that your pool should still be cleaned over the cooler period and water balance tests taken to ensure that any problems are identified early.


A step-by-step guide to Winterising your pool


  1. Don’t simply turn the filter off and forget the pool for 3 or 4 months. This is a false economy because the time, effort and money needed to get the pool water correctly adjusted next season, will be far more than the little resources required to maintain it during winter
  2. Balance your pool water correctly
  3. Take your pool cleaner out of the pool (Automatic, Suction, pressure or Robotic Pool Cleaner)
  4. Take the vacuum plate out of skimmer box
  5. Clean your pool filter/s
  6. If you have a sand filter, simply backwash and rinse it and add a good pool clarifier
  7. If you have a cartridge filter, remove the filter element and clean it. Note: Filter cartridges should be de-greased.
  8. Place the filter in position and turn the system on
  9. Treat and prevent Phosphates (food source for algae). Shake the Starver and pour down skimmer box while system is running. Note: Pool water may turn white if the concentration of phosphates is heavy, as it is killing the phosphates instantly.
  10. Pour Winteriser Algaecide into a bucket, mix with water and disperse around the pool. Note: When applying Winteriser Algaecide bubbles on top of the pool water may occur
  11. Run the system for 24 hours and then auto times (eg: 8 hours per day) for one week
  12. Backwash or clean cartridge after 1 week
  13. Change your running times for your pool for winter to 4-6 hours per day. If you own a salt chlorinator, chlorine production levels need to be adjusted to a lower setting
  14. Re-test your water and then continue to inspect and test pool water ever 2 weeks in winter


Having carried out these procedures it should only be necessary to check the chlorine level every 2 weeks and empty the skimmer basket if it has a build up of leaves etc.  This simple procedure will ensure that your pool will be ready for the first warm days of Spring and Summer and save you the expense of a costly Green Pool.

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