Blackjack Surface Technology Ltd Pav Klean Xtreme Black Spot Lichen Remover Paving Cleaner 5 Litres Fast Acting Less Than 1 Hour

this stuff does what it says you have to do the bad one may be more then once but it works

I followed the instructions to letter.Two solutions were used, one that was diluted and the other was concentrated. Safe to say, neither made a difference.Black spots - not affectedLichen - affectedMoss - killedI bought this to remedy black spot but the product failed.

Did exactly what it said. No stains or marks keft