Free Delivery On Orders Over £50



Mustard algae (also known as yellow algae) are commonly mistaken for dirt at the bottom of the pool. This form of algae normally grows on shady areas of the pool and is often mistaken for pollen. Common prevention techniques, keeping a chlorine level between 1.0 ppm and 3.0 ppm, brushing at least once a week, running your filter at least eight hours a night, and reducing the amount of phosphates, will all help keep algae out of your pool

What to do:

Ensure your water is properly balanced. The most important reading is pH. If just using Liquid Shock, your pH should ideally be between 7.3 and 7.6. This optimises the sanitising power of the chlorine in your pool.

Check your filter to make sure it is working properly. If you discover any problems or need to clean the filters, do it before treating the algae. Without proper filtration, the algae will not be able to be removed from the pool.

Thoroughly brush the pool. Be sure to use a brush that is suitable for your pool lining. Don’t forget those hard to get at places, behind the ladders and around the light fittings. The more diligent you are on this step the more likely you are to prevent a recurrence

Apply a high dose of Liquid Chlorine. When applying chlorine to treat algae the ideal time is in the evening. Leave filter running.

If after 12 hours you can see no change in the colour or the amount of algae then add more Liquid Chlorine. You may have to repeat this a number of times but do not worry, you cannot over dose with Liquid Chlorine as it will all be burnt off in 48 hours.

24 hours from the last Chlorine addition backwash the system or chemically clean your filter cartridge. The cartridge can be cleaned in a bucket with some Liquid Chlorine but please make sure you wear non-porous gloves.

When the chlorine level has reduced to 5.0 ppm add an algaecide and brush the pool again then vacuum to waste. If the water is still cloudy at this time then add a clarifier to bind the fine particles together so that the filter can trap them.

Continue running filter until water is clear.