• Fence with green algae
  • Plastic letterbox with algal growth
  • Nostoc slime colony in gravel area
  • Fence with green algae
  • Plastic letterbox with algal growth
  • Nostoc slime colony in gravel area

Our Personal Guarantee


Get rid of the slimy, green growth of algae on outdoor surfaces.


Algae are simple, single or multi-celled, plants. The alga found around your home will be seen as green 'slime' or colouration to surfaces such as paths, drives, decks and fences. Algae are green because they contain chlorophyll for collecting light energy to grow. They are able to get nutrients from the surface they are living on and from the rain they keeps them damp. They thrive in damp shaded areas or when the weather becomes cooler and the sun is less strong. They can survive drying out but spread and grow more quickly when they stay cool and damp as in autumn and early spring. These are the best time to treat them with Sorted Moss and Mould or Sorted Tough Stains , but they can be treated anytime.

Nostoc is a colonial cyanobacteria (blue-green alga) slime which swells up into a jelly like mass when wet. It is bluish-green, olive green or brown when wet but in dry conditions it becomes an inconspicuous, crisp brownish mat.


Removal and prevention of algal and Nostoc growth

If your outdoor surface is stained with algae, moss, black moulds, lichen or other biological growth, use Sorted Moss and Mould . This powerful targeted formulation kills and prevents damaging moss, mould, algae and lichen. It goes on to protect the surfaces all season long. This hose end sprayer is easy to use; simply click the pack onto the end of your hose and spray on and leave, without rinsing off. Sorted Moss and Mould penetrates the surface killing the damaging organisms and they will then weather off over time. 

Sorted Moss and Mould kills and prevents moss, mould, liverwort, lichen and algae.

For Nostoc in lawns use LawnPro Mossclear .

For Fast Spot Treatment

For small areas of hard to remove green algae spray with Sorted Tough Stains . This handy trigger pack is ready to use and removes many tough stains in seconds with an advanced formula that is stronger for longer. Be aware, Sorted Tough Stains contains bleach and may damage some surfaces, check the Sorted Tough Stains page for more information.

Sorted Tough Stains removes staining caused by algae, mould and many other marks.

Did you know

Common names include star jelly, witch's butter, mare's eggs, fah-tsai and facai.

Deals with Algae

View all products