A brief guide to maintaining a pool

Maintaining a pool, whether in-ground or above-ground, not only gives you inviting, clear water but also protects bathers from the risk of infection and guards against corrosion. Chlorine or salt? Getting rid of algae? And what about heating? Follow the guide.

Chlorine, salt and other pool maintenance products

These products must be handled with care. In pure form, most of them are toxic. Read the instructions carefully.


Chlorine (Cl) cleanses the water and helps prevent bacterial, viral and parasitic infections. While granules generally cost less, chlorine pucks require less attention (they last longer!). The liquid form, widespread a few years ago, is less common now. What’s important is to compare the chlorine concentration (60% to 75%). Obviously, the higher the percentage, the less you’ll use.

Check the chlorine level every day (especially during a heat wave or on days of heavy use). The ideal level, measured by mixing your water sample with a few drops of orthotolodine (included in your analysis kit), should be between 1 and 1.5. Adjust as required. Always add chlorine to water and not the other way around, as this could cause an explosion.

You can cut down on maintenance work by using a chlorinator, which controls the quantity of chlorine released into the water by means of concentrated pellets that last five to seven days. This system is also very effective if you’re going to be away. Otherwise, ask a friend or a qualified technician to handle the maintenance of your pool. Adding products in large quantities is not the best solution.

Maintaining a pool with a salt system

Like chlorine, salt systems disinfect the water without the storage or handling problems of chemicals or the physical discomfort of using them. Maintenance becomes easier. How does it work? Saltwater (at a concentration about 15 times lower than sea water) goes into the unit, the salt is broken down by electrolysis, and it releases natural chlorine. The chlorine is returned to the pool. Once its job is done, it is converted back to salt and the process starts again.

A weekly check of the water’s pH level is usually sufficient, since natural chlorine (resulting from the process explained above) does not evaporate like chemical chlorine, and its concentration is rather stable, unless a large quantity of water is added. When the salt level goes down, a light on the power supply will come on, and you just have to add more.

The drawbacks? Salt is highly corrosive, and this treatment is not recommended for metal-walled pools. Also, you need to use an algaecide, because salt, unlike chlorine, does not perform this function. In addition, this method has environmental impacts. During backwashing and emptying of the pool in the fall, some of the salt gets into the ground or the sewers. This excess sodium accumulation can cause corrosion and may also contaminate waterways and groundwater.

Auxiliary systems to lower the use of chlorine or salt

Auxiliary treatment systems are available to help cut down on the use of chlorine or salt. These include ozone generators, ionizers and UV sterilizers. The cost of these devices varies between $1,000 and $2,500, plus periodic replacement of some components, but the benefits are real: water that’s more pleasant for bathing, lower environmental impact and 50% to 90% less use of chemicals.

pH corrector

Is the water in your pool whitish and cloudy? Your pH may be too high. The pH level indicates the water’s relative acidity or alkalinity, on a scale of 0 to 14. The ideal level is 7.4. Several types of pH analysis kits are available on the market, in bottles (red phenol) or in tabs. Though the quality of these products is much the same, some are more complete and provide a greater variety of analyses.

Limestone stabilizer to rectify water hardness

The amount of limestone in water determines its hardness. It is important to check this property occasionally, using a kit. When water isn’t hard enough, it becomes corrosive and may damage your pool’s components. The chlorine you put in will have no effect. If need be, add a calcium-based product. But if the water is too hard, it cannot be softened and will have to be changed.

Algaecide to fight off algae

When you put your hand against the pool walls, do they feel slippery? Is the water a little sticky and slightly greenish? This means algae are developing. The water is probably too warm, and the residual chlorine is no longer effective. It’s time to add an algaecide. Examine the manufacturer’s chart carefully and add the quantity indicated for the volume of your pool. Note that algaecides have no effect on bacteria or viruses.

You haven’t discovered what’s causing cloudy water?

You’ve used all the tests in your kit and still haven’t detected the problem? Take a sample and bring it to a pool store for a full analysis. The experts will be able to identify what’s wrong and to suggest a solution and a “dosage” in line with the volume of water in your pool.

What products do you need to close your pool?

The products used to prepare for winter are usually the same as for regular maintenance. However, the dosage will be higher. Adding chlorine and pH stabilizer are just some of the many steps for closing a pool.

Heaters for pools

Water heaters are ideal for advancing or extending Quebec’s all-too-short bathing season. Various types of device are available: conventional, solar or a combination of the two.

Heat pumps

Heat pumps are by far the most efficient of so-called conventional water heaters, followed in order by natural gas, electric and propane water heaters.

Pool heat pumps can provide an energy performance of about 450%, while electric water heaters are limited to 100%. The ratio to be met for heat pump power is as follows:

  • 1 BTU/litre for a sunny location
  • 1.5 BTU/litre where there is less sunshine

Heat pumps, like electric water heaters, often have to run day and night due to their slow pace of water heating. In addition, both types of device require installation of a high-amp (220-volt) electrical panel and a circuit breaker with a safety switch.

Natural gas or propane pool heaters

Natural gas or propane pool heaters warm the water more quickly than heat pumps. They need to run just a few hours before the water is ready for bathing. The energy efficiency of these devices is 80%, but natural gas heaters are far more economical due to the low cost of the fuel.

However, there are installation constraints:

  • Natural gas: requires the presence of a distribution network (Énergir or Gazifère).
  • Propane: requires installing a tank (check on municipal regulations) and arranging fuel delivery.

Solar pool heaters

Solar pool heaters require no upkeep or energy spending, and they are quiet and non-polluting.

The panels (collectors) are usually installed on the roof of the house, garage or shed. Water is moved by the pool pump and flows through a series of small pipes that absorb the sun’s rays and transfer heat to the water, which is then released into the pool. A valve needs to be operated manually or automatically, morning and night, or when the sun comes out. A thermostat can also order the automatic closing of the supply valve when the desired temperature is reached.

The drawbacks of solar pool heaters? Their effectiveness depends on which direction the solar collectors face and even more on the amount of sunshine. While the water temperature can easily climb by 3°C to 4°C per day, it doesn’t go up on rainy or heavily overcast days. Ideally, adding a solar blanket will let you cut heat loss at night or on cool days by 50%. In addition, a more powerful pump may be necessary if the distance between the pool and the collectors is too great. Also, beware of unapproved low-quality systems, which can cause water leaks at the joints or moisture accumulation under the collectors, risking damage to your roof.

Solar (or insulating) blankets

In terms of energy efficiency, this offers the best performance on the market in relation to cost (from $45 to $200, depending on pool size):

  • It reduces cooling of the water (in overcast weather or at night), evaporation and the required quantity of cleanser.
  • A rewinding reel eases handling.
  • Its lifespan is four to five years if used and stored (in the shade) properly.

Leaving the blanket in place for more than 48 hours is not recommended. This prevents oxygenation of the water, favouring algae proliferation in particular. To be avoided!

Source: https://www.caaquebec.com/en/at-home/advice/tips-and-tricks/tip-and-trick/show/sujet/a-brief-guide-to-maintaining-a-pool/