Pool Shock Treatment: When and How?

You’ve been away for two weeks and when you come back you find a swimming pool with water so green that it looks like a swamp, even frogs would hesitate to dive in. To regain the clear water of yesteryear, you will need to use the strong way: the liquid pool shock treatment. But do you know how to shock a pool effectively?

In contrast to the traditional preventive treatment, pool shock has a curative purpose and should be used occasionally, ideally, as little as possible because it significantly modifies the concentration of treatment products in pool water. If your water is disinfected and filtered properly you should not need many shock treatments per season.

When should I Shock my Pool?

  • Following a pool party! (large number of swimmers)
  • Following a storm (especially rain).
  • The sudden invasion of algae.
  • At the end of the season, before wintering.

Precautions to be taken before a Pool Shock

  • Stop all swimming.
  • Remove all accessories and objects from the water.
  • Remove coarse impurities with a landing net.
  • Clean your pool and filtration thoroughly.
  • Set your filtration to forced operation (manual operation).
  • Analyze and balance your water (especially the pH) according to the product you are going to use.

pool shock splash perfectWhich Pool Shock to Use

– If you treat your water with chlorine:
In this case, the product that you need to use, first and foremost is chlorine. To treat your water, place the shock chlorine (in powder, pellets or granules) in each skimmer of your pool, respecting the dosage prescribed by the manufacturer. Wait 24 hours for the chlorine to dissolve completely. For optimal effectiveness of shock chlorine treatment, ensure that your water has a pH below 7.5. If you usually treat your water with chlorine, you can also use active oxygen to perform a shock treatment. Active oxygen is more effective but is also more expensive.

– If you treat your water with bromine:
For this treatment, you can use Bromine, calcium hypochlorite (HTH) or unstabilized chlorine (sodium hypochlorite) combo. Stabilized chlorine is not recommended to be used in combination with Bromine. Bromine shock has maximum efficiency with a pH between 7.5 and 8.2.

How to Shock a Pool

The basin must be cleaned beforehand, the walls like the bottom brushed and the filter washed. The pH should be adjusted to levels that optimize the effectiveness of treatment: between 7.2 and 7.4. In case of hard water, an anti-lime treatment can also be carried out. The disinfectant products are distributed evenly over the entire surface of the pool, not in the skimmer. Except in case of packaging in liquid or powder form, it is advisable to dissolve the product in a watering can not risk staining the coating.

The filtration must then run continuously for at least 12 hours (or even longer if the turbidity of the water persists) to ensure complete mixing of the pond.

Manufacturers will have a detailed instruction on how to shock a pool using their products. When in doubt, always read the manufacturers label.

Now that you have learned how to shock a pool, it is important to note that the water can be cloudy after a shock treatment. This is usually due to dead algae that remain suspended in the water after the treatment. Indeed, if there were a lot of algae, the filtration system is not always sufficient to eliminate the waste. In this case, the use of a bottom flocculant can solve the problem, thanks to this product, the floating waste will stick together and fall to the bottom of the pool, you will then have to remove them with a vacuum cleaner or robot to find clear water.