GK Black Spot Remover is a high-performance cleaner designed to easily remove black discolouration and microbiological contaminants from porous surfaces such as stone, render, block paving and concrete. It is a thixotropic, slightly viscous, non-penetrating liquid and has a unique alkali formula containing wetting agents for the removal of organic and non-organic staining.

GK Black Spot Remover can be used before or after GK Pro biocidal treatment, or as a stand-alone treatment. It thins when agitated allowing good contact with surface contamination, it is non-invasive and allows extended dwell time for the active ingredient to do its work. Brush it in and leave for up to 24 hours (depending on need) then rinse the surface.


  • Can be applied by brush, sponge, roller or extending pole
  • Powerful effective cleaner for stubborn fungi, lichens and algae
  • Does not alter the appearance of the surface
  • Fast-acting
  • Low odour
  • Acid Free
  • Biodegradable
  • Removes and controls organic soiling
  • Average coverage 8m²


  • Always test on a small area of the surface to check compatibility and performance before commencing with the whole area
  • Remove loose dirt, moss and other debris from the surface to be treated. A broom or firm bristle brush is ideal.
  • Do not use in wet weather, frost or if rain is forecast within the application period. If used when temperature is below 8⁰C the effectiveness may be reduced and longer cleaning time may be required.
  • Keep pets away until the surface is fully washed and dry.
  • Ideal application temperature between 10⁰C and 30⁰C.
  • The longer GK BSR is left to work (up to 24 hours) the brighter the surface will appear.
  • It may help the process to slightly wet the surface prior to application.
  • NOT recommended for use on wooden surfaces 
  • Whilst applying, appropriate PPE should be worn. We recommend protective gloves and eye protection/face protection as a minimum requirement.
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