How do I remove Green Algae from my patio?

Green Algae growth on outdoor surfaces is a problem for homeowners throughout the UK.

Keeping your patio slabs and fencing clean is often overlooked compared to cutting the grass in your garden. It is worth remembering that without proper care, green algae and moss can start growing on patios, stone floors, stone walls or fencing. This can lead to damaging your stone’s appearance as well as can pose a risk of a slippery floor, which can be quite dangerous.

One of the ways to remove algae from your patio would be using a dedicated algae remover such as Rob Parker’s Best Algae Remover. In this blog post, we will explain how to properly clean green algae from your stone.

Why do I have green algae on my patio?

Green Algae will normally form on areas of your patio where light is restricted.  Under the shadow of trees where rainwater lingers is the perfect setting for green algae to thrive.

Affected surfaces become slimy when wet. This causes a slip hazard where accidents can potentially happen. If algae is left to dry over the summer it will turn black and make the patio look dark and dirty, providing ideal conditions for the process to begin again the following winter.

In damp but mild conditions (hello UK!) green algae can be prolific!

How do I remove Green Algae from my patio?

Available methods of algae removal:

  1. Power washing: this will remove the algae but may also damage the patio surface and grout creating more work.
  2. The easy solution is to apply a proprietary algae remover/inhibitor.

Choose your algae remover carefully as there are many products available that are simply derivatives of bleach. These will remove the colour of the algae but not remove the problem. Solve the problem correctly with an effective spray on algae killer.

Rob Parker’s Best Algae Remover and Patio Reviver will kill green algae.  This treatment will kill and remove the green slimy stains, restoring your patio.

Buy Rob Parker’s Best Algae Remover

Rob Parker’s Best Algae Remover and Patio Reviver
From £11.40/Each

How can I stop green algae from growing on my patio?

Using a specific algal killer such as Rob Parker’s Best Algae Remover and Patio Reviver, will not only kill the green algae that are present; it also provides residual protection to the paving for up to 12 months preventing further algal growth.

The product works gradually. Over a period of days daily improvement can be seen in the stone surface.  The formulation works in conjunction with atmospheric conditions (sun, rain and air temperature) giving ongoing protection against further build-up of green algae throughout the season.


Furthermore, if the product is applied every year, at the same time, the problem can be permanently solved.

Use Rob Parkers Best Algae Remover & Patio Reviver as a Preventative Treatment

At Stoneworld we apply Rob Parker’s Best Algae Remover and Patio Reviver to our paved areas every September as a preventative measure. When the weather begins to turn damper and cooler at the beginning of Autumn, green algae can take over. Protect your patio against growth through the winter rather than allowing algae to grow and then killing the algae once you have it.

How do I apply Rob Parkers Best Algae Remover & Patio Reviver?

Using our product is easy!

Simply spray onto affected surfaces using a garden sprayer.

The product is sold in small 250ml bottles that we ask you to dilute with 8 litres of water before use. This makes enough to cover 25 square metres.  By selling the product in a concentrated format we can save on packaging. 

At Stoneworld we recommend Rob Parker’s Best Products for your care and maintenance jobs on stone surfaces.  We have developed our stone care range in conjunction with chemists to ensure that good results can be achieved, offering stone owners total stone care solutions. 

Other products in the range

Rob Parker’s Best Patio Cleaner
From £17.50/Each
Rob Parker’s Best Patio Sealer
From £35.00/Each
Rob Parker’s Best Rust Remover
From £26.50/Each

What happens if I do not remove the algae from my patio?

Lack of sun exposure as mentioned above causes algae to recur every season, causing damage to your patio and slipping hazards for yourself, which complicates the algae removal process. The main effect of not removing algae is discolouration. At first, it appears as yellow, then green and later becomes dark black, especially during winter months. If you find developing black algae, you are very likely to start considering power washers as hand liquid products for algae removal might not be strong enough on their own to fully cleanse the area.

We have more than 20 years experience with algae removal and our products range from simple to complex which allows you to fully get rid of algae and its occurrence. See our recommended algae removal products above.