How to avoid green water problems

One of the causes of algae growth is an acid-base imbalance in the water. By analysing the parameters of your pool water, particularly the pH, you can see whether the water is too acidic (pH too low) or too basic (pH too high). Generally speaking, a pH above 7.6 encourages algae growth. If the water is naturally very hard or very acidic, it needs to be rebalanced frequently. Water rich in minerals and trace elements also encourages algae growth.

Solution : 

Before any treatment, it's essential to regularly measure the pH of your pool water using one of our analysis accessories.  A pH that is too high or too low minimises the effectiveness of pool care products and encourages the growth of algae. The ideal pH of water is between 7.0 and 7.4.

Although warm water is particularly popular with bathers, it is also a risk factor. A sharp rise in temperature, unstable and stormy weather, heavy rain or external contamination all encourage the appearance of algae in the pool. The heat also causes chlorine to consume more rapidly.

Preventive measures:

Add fresh water frequently, and check and adjust the pH in stormy weather. By increasing the amount of chlorine in the water, you can limit the risk of the water turning sour.

Clogged filters or filtering for too short a time during the day can cause green algae to develop. A faulty or broken-down filtration pump is also a factor to consider.

The right things to do:

• If you have a cartridge filter, clean the cartridges more frequently, as they quickly become clogged. Finally, change the filter media or cartridges before they reach the end of their life.
• If you have a sand filter, check the pressure gauge regularly, which will indicate a filtration fault. Clean the filter by backwashing regularly, on average once a week (as soon as the pressure gauge increases by 0.2 to 0.3 bar compared with the pressure when the filter is clean).

Intensive use of the pool by large numbers of people can be an aggravating factor. Swimmers naturally pollute the water with ‘organic’ matter (sweat, hair, sun cream, etc.). Similarly, inadequate maintenance of the pool can encourage the growth of algae. If the skimmers are not emptied, if the net is not used and plant debris accumulates at the bottom of the pool, phosphates, the main source of food for algae, can rise.

Simple solutions:

Clean the pool frequently (once a week) and invest in a robotic cleaner. If the pool is used intensively (especially if there are children), you can install a foot bath, as in a public pool. This chlorinated water tank will remove leaves, dirt and dust that pollute the pool. Finally, advise anyone using the pool to shower before diving in.

Although essential, measuring phosphate levels is often overlooked. That's why we've developed a new Phosphate Test Strips kit that allows you to analyze the phosphate levels in your pool water. Quickly and easily.

For anyone who has recurring algae problems in their pool due to excess phosphates in the water, we offer Nophos, a highly concentrated liquid treatment that is compatible with all treatment methods and filtration systems. It is an effective way to prevent algae growth by acting directly on the phosphates they feed on and enhancing the action of disinfectants and algaecides. With Nophos, phosphates are agglomerated, retained in the filter, and then eliminated.

For curative action

In case of recurring algae problems or high phosphate levels in the water (> 0.1 mg/l), pour 50 ml of Nophos per 10 m³ of water directly into the skimmer. After treatment, if the phosphate concentration is still high, repeat the dosage.

For preventive action

• If you have a cartridge or diatom filter, pour Nophos directly into the pool in the evening after swimming, at a rate of 20 ml of product per 10 m³ of water, in front of the discharge nozzles, with the filtration system running.
• If you have a sand filter, place Superflock Plus, a flexible flocculant cartridge specially designed for sand filters and containing lanthanum, a highly effective anti-phosphate agent, in your skimmer basket. The product acts effectively and continuously against cloudy water while eliminating phosphates.