Balancing Pool Chemicals for Different Seasons

a close up of a leaf on the ground.

As we move out of summer and into fall, you will be using your vinyl liner pool less frequently. Even so, keeping your chemicals properly balanced moving into fall is just as important as it has been in the summer. Maintaining your pool during the cool months of autumn and preparing it for the cold months of winter is critical for finding your pool in good condition when you’re ready to start using it again next year. As you know, sustaining good pool chemistry is the only way to keep your pool clean. And, over the long winter months, you definitely want the resting pool to be in good shape. So, is it necessary to change the chemistry of the pool’s water in the fall from what it has been in the summer? Here is a guide we have put together to help you maintain optimum water quality going forward.

Balancing chemicals in the pool for seasons changing

During the Summer

During the summer, it’s hot and people are using the pool regularly which changes the water’s chlorine levels constantly, as does sunlight. Sunlight decreases the time chlorine is effective so you need to test the water more often to ensure that the pH level and alkalinity are stable. It is a best practice to test the pool water once a week in the summer to make sure it is balanced and free of bacteria and algae. Chlorine levels should be between 1 and 3 PPM and pH levels should be on the lower end of 7.2 and 7.8. The pH level is the most significant factor because if it is too high there isn’t enough hypochlorous acid generated from the chlorine to kill harmful germs and bacteria.

Into the Fall

The temperatures in the fall are still very temperate in our region, so it’s possible you could be continuing to use your pool. Stay with the same maintenance routine as you practiced during the summer. The chemical balance should be about the same since you will still be in the pool. But, as the temperatures begin to cool down and you move closer into the winter months, you need fewer chemicals to keep a stable level. Just keep monitoring the pH and chemical levels as the temperatures cool and adjust as needed.

When you cover your pool to protect it from the falling leaves and the elements in colder weather you will want to prevent breeding unwanted microbes in the dark water. Even in the winter, continue to monitor the pH and chlorine levels so you don’t find slimy walls and a big mess when you open the pool in the spring. Here are some specialized chemicals to use in the cooler seasons:

  • Concentrated winter algaecide – This is a much stronger algaecide that prevents algae growth and changing water color.
  • Chlorine shock – This raises the pH level to a higher level as compared to regular chlorine in order to keep the pool clean for the storage period through the winter. You can learn how to shock a vinyl liner pool here.

Chemicals that Keep the Water Clean and Safe

Here is a list of the regular chemicals to use in keeping the pool water clean and safe:

  • Chlorine
  • Balancers
  • Algaecide
  • Flocculant/Clarifiers


Chlorine keeps the water clean and safe to swim in. It attacks and neutralizes harmful bacteria and microorganisms by killing germs that make people sick with such illnesses as swimmer’s ear and diarrhea. It also prevents the growth of algae.  Chlorine causes a simple chemical reaction when it enters the water by breaking down into two molecules, hypochlorous acid and hypochlorite ion. These chemicals attack the lipids in the cell walls of microorganisms, killing them so they become harmless. Both chemicals are vital to the hygiene of your pool.


Balancing your pool water and keeping pool chemicals in their ideal ranges help ensure that your water isn’t harmful to people in the pool. Balancers maintain the pH balance and the alkalinity levels for the pool water. Total alkalinity levels, pH levels, the amount of calcium, stabilizers, and total dissolved solids are maintained by using balancers. If pH or total alkalinity is too low, chlorine can rapidly delete. Low pH can corrode pool equipment and irritate the skin. When pH or total alkalinity is too high, the pool water may be cloudy and the chlorine will not work efficiently.

Balancers fall into these categories:

  • Alkalizers – Alkalizers such as baking soda or soda ash balance low pH.
  • Acids – Acids such as muriatic acid or dry acid (sodium bisulfate) adjust the water’s chemical balance when pH or alkalinity is too high.
  • Conditioners – A conditioner like cyanuric acid counteracts unstabilized chlorine. Stabilized chlorine already has a base pool conditioner added.
  • Calcium Hardness Increasers – If you have soft water, your calcium hardness level is too low and can corrode pool surfaces. Increase calcium hardness levels with calcium chloride.


Add algaecide to your pool water weekly. Algae in your pool can affect the fun for everyone trying to have an enjoyable experience. An algaecide is a backup to the normal sanitization routine by preventing algae from starting and growing in the pool. Algaecide can be added after every shock treatment.


Floating oils, debris, and other particles floating in the water can cause it to be cloudy. These particles can be too tiny to get picked up by the filter. In this situation, use either a clarifier or a flocculant. Both create a negative charge that magnetically binds to the particles and causes them to collect in bigger clumps. With a clarifier, the large clumps get trapped by the filter. If a clarifier isn’t doing the job, then use a flocculant, also called “pool floc,” to bind the tiny particles. The difference between a clarifier and a pool floc is where the particles go after they are clumped together. The clarifier keeps the bounded material on the top of the water while a pool floc sinks them to the bottom of the surface. A pool floc works much faster than a clarifier so if you need the water to clear up quickly, use the pool floc.

Contact Prestige Pools for Your Vinyl Pool Installation

Regardless of the season, it’s important to keep the pool chemicals balanced. If you are interested in an in-ground vinyl liner pool installation, please call us at 919-586-8556 or reach us through our easy-to-use contact form.