Swimming pool and spa cleaning

Cleaning your swimming pool or spa

People who use your swimming pool or spa can get sick if you don't clean the water properly. Possible illnesses include ear infections, stomach infections, and skin rashes.

Swimming pools and spas are good places for microorganisms like bacteria and viruses to live. Even clear water can have microorganisms in it. Good cleaning reduces the numbers of microorganisms to safe levels.

To keep your pool or spa safe, you must test your water on a daily basis, especially when it’s being used a lot. Always maintain proper water balance in all types of pools and spas, even inflatable and kiddie pools.

How do I clean my swimming pool or spa?

Traditional pools or spas

Chlorine-based and bromine-based products are good sanitizers, and they also control algae. You can buy chlorine and bromine as a chemical (pucks, tablets, or liquid) or buy a device that makes hypochlorous or hypobromous acid from salt to clean the water. Some types of chlorine or bromine can also be applied using a dispenser.

Saltwater pools or spas

You must use a chlorine- or bromine-generating device to clean the water. You can’t use chemical products.

Ask a pool and spa professional what the right treatment is for your pool or spa.

How much sanitizer should I use?

It is important to follow the directions when using swimming pool and spa chemicals. The label tells you how much of the product to use and how to handle the product safely. Always read the label before using any product.

Swimming pool and spa devices that generate or dispense a sanitizer have detailed instructions in the user's manual, on the package, and on the device itself. Always read the label and the user's manual before installing and using a device.

Controlling algae

Algae are plant-like organisms that live in water. They are not usually harmful to people. But they can create a potential hazard by making pool and spa surfaces slippery and water cloudy. Algae also make sanitizers less effective. When more of the sanitizer is used up to control algae, it is easier for bacteria and viruses to multiply.

Hot weather, sunlight, and low sanitizer levels can encourage algae growth. Using a sanitizer regularly should prevent too much algae growth. But you may also need algicides to tackle big algae problems, like products containing copper sulphate or quaternary ammonium chloride. Devices that release metal ions into pool or spa water can also be used to control algae.

How should I use copper sulphate algicides?

Copper sulphate-based swimming pool algicides can be used to:

  • control algae
  • improve water clarity
  • reduce the amount of chlorine- or bromine-based products needed

They do not:

  • control microorganisms like bacteria and viruses
  • eliminate the need for sanitizers

Copper sulphate-based products must be used along with chlorine- or bromine-based sanitizers to protect bathers.

Note: The amount of copper sulphate-based algicide needed will vary depending on the size and type of your pool and its location.

Are copper sulphate algicides safe?

Health Canada has found that using copper sulphate-based algicides in swimming pools is not dangerous to swimmers. If you follow all label directions, copper sulphate algicide should not cause skin irritation. But you must be careful when handling undiluted products, to reduce the risk of skin irritation.

Using pool and spa devices

There are four types of devices used in swimming pools and spas:

  1. Chlorine and bromine generators use electrical energy to produce acid from salt, which in turn cleans the water. Chlorine and bromine generator devices must be registered by Health Canada.
  2. Chemical dispensing devices automatically release acid from chlorine or bromine chemicals into swimming pools. The user's manual should be carefully followed. Chemical dispensing devices for swimming pool use do not have to be registered.
  3. Ionizers produce metal ions to control algae. You must still use chlorine-based or bromine-based products for cleaning. Ion and disinfectant levels should be checked often and electrodes replaced as needed. Ionizers must be registered.
  4. Ozone-generating devices can be used to reduce organic matter in pool and spa water. Although these devices can be used with chlorine-based or bromine-based products, they do not replace them. The main purpose of ozone-generating devices is to oxidize organic matter. Ozone-generating devices do not have to be registered, unless they make claims to control microorganisms like bacteria and viruses or to control algae.

When using ionizers or ozone-generating devices, you must still use chlorine-based or bromine-based products for cleaning. A proper level of sanitizer must be maintained in order to prevent the spread of disease-causing microorganisms.


Always read the label and the user's manual before installing and using a device.

Using registered or scheduled products

All pool and spa products (chemicals and devices) used to control microorganisms and algae must be registered or scheduled under the Pest Control Products Act. Health Canada reviews registration applications for possible risks to human health and the environment, and to see how well the product works.

Registered or scheduled products have labels with directions and information on how to use them properly. Registered products are easy to spot. Just look for the five-digit registration number on the front of the package, in one of these formats:

  • Reg. No. 00000 PCPA

Scheduled product labels will say "Scheduled under The Pest Control Products Act.”

Other pool and spa products (like pH adjusters, shock treatment, chlorine neutralizers, and devices used only to dispense pool and spa chemicals) do not have to be registered. This is because they do not control disease-causing microorganisms or algae. If you are in doubt about whether a product you are considering is subject to the Pest Control Products Act, please contact the Health Canada Pest Management Information Service.


Avoid products that are not clearly labelled. Use only registered or scheduled products, and follow all label directions.

Testing your water

To keep swimmers and bathers safe, you must test your water balance daily for sanitizer levels, pH, total alkalinity, and calcium hardness.

Whether you choose chemical products or electrical devices to clean your pool or spa, you must maintain a certain amount of sanitizer to prevent disease-causing microorganisms from multiplying. Also, you must maintain water balance and a proper concentration of copper-based algicide to prevent staining pool surfaces.

The exact amount of sanitizer you need depends on many factors:

  • the number of bathers
  • how often you use your pool or spa
  • contaminants in the water (like suntan lotions and oils)
  • water temperature
  • the amount of recent rain

You must test daily to figure out if the level of sanitizer in your pool or spa is enough to protect swimmers from disease-causing microorganisms. Water testing can be done using good quality test kits you buy from a store. You can also bring water samples to your swimming pool or spa dealer.

Recommended minimum level of sanitizer

The level of sanitizer in your pool or spa is called "free available chlorine or bromine.”

The recommended minimums are:

  • residential pools including kiddie pools and inflatable pools: 1-3 ppm
  • residential spas and hot tubs: 3-5 ppm
  • commercial pools: provincial and/or municipal regulations must be followed

Organic matter like tree leaves and grass makes sanitizers less effective. In some cases, the label directions on swimming pool sanitizers and algicides may tell you to maintain a minimum chlorine level of 0.6 ppm. Reducing sanitizer levels from 1-3 ppm (as recommended above) to 0.6 ppm is possible only when you control the organic matter in your water.

Note that the 0.6 ppm chlorine level applies to pool water only. Spa water must be maintained at 3-5 ppm.

For complete instructions on maintaining proper sanitizer levels, follow all directions on product labels.

Safety tips

Before using swimming pool and spa chemicals

Read the label and follow all instructions.
Keep all chemicals away from children and pets.
Wear proper protective equipment and clothing, like gloves, goggles, and footwear.

When using swimming pool and spa chemicals

Use separate, clean metal or plastic measuring cups for each chemical when measuring.
Add the chemical to the pool water (unless otherwise noted on the label).
Keep chemicals away from food surfaces like counters, tables, and stovetops.
Wash your hands well after handling any chemical.
Do not smoke, drink, or eat while using chemicals.
Do not use contents of unlabeled containers.
Do not mix different chemicals together or put spilled chemicals back into their containers.
Do not touch undiluted chemicals with your hands.
Do not generate dust when cleaning up a powder or solid. The dust can react with moisture on your skin and cause injury.
Do not expose chemicals to heat or flame.
Do not use a "dry chemical" fire extinguisher if a fire breaks out. Only use large amounts of water. If you can't extinguish the flame immediately, leave the area and call the fire department.

In case of poisoning or injury

  • Get medical help or call a poison control centre right away.
  • In case of accidental poisoning of a pet, get veterinary help right away.
  • Remove the victim from the source of contamination and quickly remove contaminated clothing and shoes.
  • Flush the contaminated area with lukewarm, gently flowing water for at least 15–20 minutes (longer for corrosives).

After using swimming pool and spa chemicals

Read and follow storage instructions on the product labels.
Keep chemicals in their original containers when not in use.
Store in a cool, dry, well ventilated place, away from sunlight.
Store chemicals away from food and beverages.
Store liquids below powders or solids.
Store pool chemicals away from gasoline, fertilizers, pesticides, grease, paints, tile cleaners, turpentine, or other flammable materials, especially when pool chemicals are stored in sheds or small storage rooms.
Throw out unused or partially used products at provincial or municipal household hazardous waste disposal sites.
Do not stack containers or store materials or chemicals above your head.
Do not reuse empty containers. Throw them out in your household garbage.


Report pesticide problems to manufacturers using the phone number on the label. They must report problems to Health Canada.

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