How to clean green pool water

Posted on Friday, 4 March 2022

If you have green pool water, discover our professional tips on what steps to take to resolve this problem.

Green water is an issue you can deal with thanks to the expert advice offered from CVX. Follow our tips to recover your pool water without having to empty or refill it. Green pool water may be down to several reasons, including algae or low water alkalinity, which is identified through its characteristic emerald, green colour. 

To know how to resolve your green water problem, there are several steps to follow, and you also need professional advice and products, such as those available in the CTX catalogue. Therefore, to resolve this specific problem, we need to undertake a series of specific duties, using the right tools and products for each case.

I have green pool water: what steps do I need to take to resolve this?

Now that we know why your pool water goes green, we need to find a solution. Firstly, we need to clean and brush down the side of the pool and the skimmer basket to remove any algae. 


Secondly, we need to  analyse the water’s pH levels to check if the values are as they should be (ideally 7.4), and, if not, we have to balance these levels out with CTX pH Minus (pH reducer) or with CTX pH Plus (enhancer). Next, we need to clean the filter with CTX Netafilter. 


Thirdly, we need to check if the pool is a liner or tiled pool, as this will define which is the next process to follow. 


In the case of a liner or polyester pool, we need to do a shock chlorination with CTX-200Gr ClorShock. Dichloride, more commonly known as fast or shock chlorine is the ideal product when cleaning green pool water or seeing how to disinfect it quickly and effectively. It is particularly useful when recovering pool water after a prolonged lack of maintenance, or for when there has been an especially high number of people in the pool. It is a neutral pH product, easily dispensed, simple to use, and quick to dissolve, resistant to any deterioration caused by the effects of ultraviolet radiation. Next, we will add in the CTX Xtreme Floc flocculant, and leave the pool to filter for 24 hours. Finally, we will add in the CTX-530C Algastop Ultra Power concentrate algicide. 


In the case of tiled pools, CTX Destructor de Algas will be exclusively used. 


To prevent this unpleasant issue of algae, at CTX we recommend using algicides, as an important part of looking after your pool water. CTX has a wide range of algicides, just ask us. 

We also recommend that you measure the phosphates in the water, as the algae feed on these, use CTX Phosfree to remove them. 


Another cause of green pool water is low alkalinity in the water. To treat this, we need to use specific products such as the CTX-21 alkalinity enhancer. The total alkalinity of the water should be between 100-150ppm. If lower than the minimum, use this product to increase the levels to help fight against the green colour of the water.

With these comprehensive treatments available from CTX, cleaning green pool water will no longer be a problem. You can also ask our experts for advice on how to work out which is the best product for each specific case.