How to clean your green water?



Despite taking great care of your pool, you may still come across green water. Don't panic, a few quick fixes and your water will become crystal clear!


Help, my water is green!

Find the cause of the problem

  • The warmer the water, the more prone it is to the proliferation of microorganisms
  • The more calcareous the water, the more prone it is to the proliferation of micro-organisms (Limestone promotes the growth of algae)
  • The more organic matter water contains, the more prone it is to the proliferation of microorganisms

Where do organic materials come from?

  • The Swimmer: Sweat, urine, saliva / Mucosal secretion / Skin particles, Hair films / Grease, Cosmetics
  • Nature: Grass, foliage, soil, dust / Pollen, algae spores
  • The environment: Soot, acid rain, grease, oil...
  • Water supply: Algae spores / Dissolved organic matter

Cleaning the pool

Before starting to treat your water, it is necessary to prepare your pool:

  1. You must use a net to clean the bottom of your pool and the surface
  2. Clean your filter and skimmer basket
  3. Brush the walls to remove microorganisms
  4. Clean your water line; use a water line cleaner that disintegrates greasy deposits
  5. Using a robot or a net, remove the last remaining debris

Water treatment

  • Check the PH level and stabilize it between 7 and 7.4
  • Perform a chlorine-free shock treatment to disinfect the water. The filtration must be running
  • Put one or more flocculant cartridges in the skimmer. Have a look at our Acti Floc Bag.
  • Use a preventive treatment against algae growth with a product like Acti Anti-Alg 3
  • Set up the filter permanently for 24 hours


Tip: Clean with water all toys, mattresses, accessories that could have been in contact with green water (contaminated with algae), and that could pollute the pool the next time they are used!

Green water can also be due in some cases to:

Over-stabilization: Check your stabilizer level > 150 ppm. Drain half of the basin; 100 ppm drain a third. Use unstabilized chlorine. Try Acti HP Shock.

Presence of Phosphate: Check the phosphate content and eliminate their presence

How to prevent this from happening again

It will be necessary to regularly:

  • Monitor the quality of your water with the pH test
  • Clean your pool regularly by removing debris, cleaning the bottom and walls with a brush or robot
  • Use an anti-algae product
  • During high heat, run the filtration system

Questions? Don’t hesitate to contact us for more information!


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    A good balance is paramount for the swimming pool’s water.

  • Why should a wintering product be used?


    Wintering is an important stage in the operating life of a pool.

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