Do I Really Need to Balance My Pool Water at Closing Time?

The Ultimate Guide to Balancing Pool Water Before Winter

Do I Really Need to Balance My Pool Water at Closing Time?

Once again it’s getting near that time of year to close your pool for the winter. School’s opening, pools are closing! Whether you’re one of those who close religiously on Labor Day weekend or someone who tries to squeeze every last drop out of the warm weather, pushing into early or even mid-October, we all know it’s getting closer to closing time.

Which means that you don’t need to balance your pool water anymore until next year, since you’re not going to be swimming in it and it will be covered, right? WRONG!!!!

If you’ve long thought that the chemical condition of your water over the winter doesn’t have any real effect on your pool and that adjusting chemical levels before closing is a waste of time and money, read this article carefully and be ready to reconsider your opinions.

So here are the questions:

“Why bother adjusting my pool’s chemicals before putting a cover on it?”

“The water won’t even be circulating in my pool, so why does it matter if the water is balanced?”

“Can’t pool chemical balance wait until spring?”

If you’ve thought this before, here’s a different way of looking at this. Keep in mind that in New England, even if you open early and close late, your pool spends roughly two-thirds of its life closed with a cover on it. So even though the water is closed off to the elements to a large degree, there is no one swimming in the pool and the filter does not run daily, remember that about 8 months of the year the water will still be in constant contact with the surfaces of the pool. The long term effects of things such as incorrect adjusted pH, insufficient calcium levels, high metal content and even alkalinity not being adjusted WILL EFFECT not only how well the chemicals you put in the pool work to keep it clean, but also will effect the condition of surfaces in the pool.

For example, low calcium levels over the winter will cause problems in the long run (although not as long as you might think). Believe it or not, plain old water is aggressive when it comes to its nature to want to dissolve things into itself. It is because of this trait of water that we use calcium to satisfy water’s urge to dissolve things. Left unchecked, water without sufficient calcium will eventually pull certain chemical compounds out of the liner that keep the vinyl pliable and resilient. This process will shorten the life of the liner. It is for this reason we recommend maintaining 100 to 300 ppm calcium in a vinyl liner pool. And calcium levels are even more critical in a gunite pool! The plaster on the floor and walls of a gunite pool require even higher calcium levels (we recommend maintaining 200-400 ppm of calcium hardness for gunite) than a vinyl liner pool requires. Low calcium in pool water cause it to be leach directly from the plaster, leading to surface etching and eventual crumbling in the plaster itself! High calcium levels, although less common, will precipitate out of the water leaving tough white scale that is difficult to remove. Be sure to adjust your calcium hardness before closing your pool!

Additionally, water with incorrect pH can cause problems as well. Many people are unaware that the pH scale is logarithmic. All that this means is that for every point that your pool water is low or high from the number 7 (middle of the pH scale), it is 10 times more acidic or basic than the next value! So the further your pH is off the more serious it becomes. Low pH is acidic and leads to corrosion of any surface that the water comes in contact with. Also, keep in mind that if your pool cover is porous and allows water to pass through, your pH will tend to drop while it is covered due to the fact that rainwater is largely acidic. High pH is basic or alkaline and may lead to cloudy water and the precipitation of metals from the water. The higher the pH the less that water is able to hold any metals in solution, and more likely that they may drop onto the floor of the pool and stain the pool. Balanced pH will also allow the closing chemicals to work at peak effectiveness and keep the pool cleaner. Be sure to adjust your pH before closing the pool!

Which leads to the next concern: Removing excess metals such as iron or copper from the water, by using a metal remover/stain preventative as needed. Be sure to test for and remove metals before closing the pool!

Last but not least, setting proper total alkalinity before the end of the season is important too. Total alkalinity has the effect of steadying the pH and resisting changes. Especially if you have a porous or mesh cover, balancing total alkalinity will help the water maintain a steadier pH when rain water is added to the pool. Too low of a total alkalinity lets the pH drop quickly without resistance. Too high of an alkalinity may lead to a cloudy pool when opening. Be sure to adjust your total alkalinity before closing your pool!

Notice a trend here??

You wouldn’t dream of not changing your car’s oil just because it spends most of the day every day not running and parked. Why let your pool’s water remain unbalanced when closing? Be sure to balance your water BEFORE closing for the season and think about the long-term effects on your pool.

Keep swimming!

Related Products

Safe-T-Zone Pool Winterizing Kit Chemicals for Pool Closing

Safe-T-Zone Winterizing Kit
Price: $69.95
Availability: In-Store and Online at E-Z Test Pool Supplies