removing black spots from concrete path
Well, I tried a fungicide (dialkyldimethyl ammoniumchloride), or
'biocide' as they call it, which claims to work on fungi, mould, moss,
lichen, mildew and algae. Left on for 3 days then washed off as
directed. From all the warnings on the bottle it looks like nasty stuff
- shame the mould didn't seem to think so, its doing just fine :-(
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