Pool Closing Water Balance

Did you know that  a water test prior to pool closing is as important as a spring time sample? Most of us forget that pool closing is a time to tidy up any unfinished business from a summer of fun.  We almost look forward to closing the pool for the season as one less thing to do once our regular back to school/work routines begin and life seems so busy again.  Don’t neglect the pool chemistry before pool shut down – that is the number 1 contributor to pool care costing more over the long term


Pool closing water balance is different from summer time chemistry

As water temperatures drop, your water actually becomes more corrosive and much harder on the delicate pool vinyl surface.  Make sure you have a winter water test done before saying sleep tight to your pool this fall.  FOLLOW THE WATER BALANCE RECOMMENDATIONS carefully – especially for TOTAL ALKALINITY and PH.  To neglect your water balance may cause irepairable damage to the pool liner.  We have seen pool liners that should last 8-10 years need replacement in as little as 2 seasons because of the simple and preventable low total alkalinity.


Pool closing water tests prevent algae in the spring

Organic materials that accumulate over the summer that are not removed can feed algae all winter long.  Just because your pool is clean and clear when you shut it down, does not mean it will stay that way.  If wastes are not gassed off and if phosphates and other food for algae are allowed to linger, a clear pool can easily be a swampy one next spring.

Pool Closing ideal water test parameters

An ideal pool closing water test can vary depending on your pool type, your choice of sanitizer (salt pools or freshwater, etc) and your pool equipment but if you follow the guidelines below, you will not be too far off good pool closing chemistry.

Chlorine in the 1-3 ppm range for total and free chlorine

Ph should be 7.6-7.8 (higher than swimming pH).

Total alkalinity range is quite large but we like to see error on the side of too high as opposed to too low in the 125-175 ppm range.

Calcium hardness should be in the 175-250 ppm range.

No free copper, iron or manganese.

A phosphate level of nil is perfect.

Borates are a real key to a quick and easy and economical pool opening and should be 31 pm or above.


If you take some time and test your water before pool closing and follow your personalized prescription for pool care, you will enjoy a worry free off season and a pool opening that will be the envy of your neighbourhood!


Also, feel free to click here for 12 tips to winterize your pool properly!





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