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How to Properly Close Your Pool for Winter? Are You Prepared with These Chemicals?

How to Properly Close Your Pool for Winter? Are You Prepared with These Chemicals?

Table of Contents

As the cold winter approaches, closing your pool becomes a top priority for pool owners. To avoid facing a green pool in spring, preparing the right chemicals in advance is key. This article will guide you through the essential chemicals needed for closing your pool and provide detailed instructions on how to use them to ensure your pool is fully protected during the winter.

How to Properly Close Your Pool for Winter? Are You Prepared with These Chemicals?
To avoid facing a green pool in spring, preparing the right chemicals in advance is key.

Clean Your Pool to Ensure Freshness

Clean, Scrub, and Vacuum the Pool

Thoroughly cleaning your pool before winter arrives is an essential step. Remove all floating debris and dirt from the pool walls, as these contaminants become harder to deal with during the winter. A clean pool not only enhances the effectiveness of the chemicals but also prevents the growth of more bacteria and algae during the winter.

Test and Balance the Water Quality

Ensuring balanced water quality before closing the pool is crucial. Use testing tools to measure the pool water’s pH, alkalinity, and calcium hardness, and adjust accordingly based on the results. These parameters will affect the performance of other chemicals during the winter, and unbalanced water quality can damage the pool surface or equipment.

Chlorinate the Pool

A few days before closing the pool, perform a chlorine shock treatment to kill any remaining bacteria and algae. Choose an appropriate chlorine shock method, such as calcium hypochlorite shock, fast-dissolving chlorine shock, or liquid chlorine. This step ensures the pool water is thoroughly cleaned before adding other winterizing chemicals.

Essential Winterizing Chemicals

Winter Algaecide

Non-Chlorine Shock (Oxidizer)

Non-chlorine shock is an effective water treatment that can remove contaminants without damaging the pool liner or surface. Using a non-chlorine shock reduces chemical residues and provides a milder cleaning method.

Stain and Scale Preventer

Stain and scale preventers effectively inhibit the buildup of metals and minerals in the pool, preventing stains and scale formation. If your pool water is thoroughly cleaned before closing and a stain and scale preventer is added, these issues will be well controlled.

Chlorine Tablets


Air Pillow (for Above-Ground Pools)

Air pillows are crucial for above-ground pools, preventing ice damage and the pool walls from collapsing during winter. If you have an in-ground pool, air pillows are usually not necessary, but you can choose to use them based on specific needs.

Are Winterizing Kits Worth Buying?

There are many types of pool winterizing kits on the market that contain various essential chemicals. These kits provide a convenient all-in-one solution, saving time and money. However, whether you need to purchase these kits depends on your specific situation. If you already have most of the necessary chemicals or prefer to adjust the use of chemicals based on your pool’s specific needs, buying individual chemicals might be more economical.

Frequently Asked Questions

What Size Pool Winterizing Kit Do I Need?

The size of the winterizing kit should be chosen based on the pool’s capacity. Generally, manufacturers offer kits suitable for pools of different capacities, such as kits for pools up to 15,000 gallons or 35,000 gallons.

Which Algaecide Should I Use Before Closing My Pool?

It is recommended to use a 60% polyquat algaecide, which is copper-free and has a high enough concentration to prevent algae growth throughout the winter without causing staining.

Should I Shock the Pool Before Closing?

Yes, you should perform a chlorine shock treatment before adding winterizing chemicals and closing the pool to ensure all bacteria and algae are thoroughly eliminated. Choose an appropriate shock method based on your pool’s specific needs, such as chlorine shock or non-chlorine shock.


Closing your pool for winter is not complicated; as long as you follow the correct steps and choose the right chemicals, your pool can be well-protected during the cold season and easily reopened in the spring. Remember to prepare in advance and ensure every step is properly executed, which not only extends the pool’s lifespan but also saves significant maintenance time and costs in the coming year. We hope this article helps you address the challenges of closing your pool and ensures your pool survives the winter in good condition.

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