Blagdon formerly interpet duckweed buster controls the spread of unsightly duckweedduckweed buster is a natural bacterial product which prevents the growth of duckweed lemna minor by modifying the water chemistry and creating conditions which prevent the spread of this problematic aquatic plantdirectionseasy dose bottleinitial dose 25ml for every 450 litres of pond watermaintenance dose 10ml for every 450 litres weekly until duckweed is no longer visiblethis product cannot be overdose