Yesterday Husband and I tackled the green algae that has conglomerated on our patio which is northfacing and never sees the sun. I started off with a cleaner called Armillatox - it was useless - I scrubbed, scrubbed and scrubbed some more. We left it over night - the patio still leered "green" at us. Husband scrubbed on dettol and we both smelt of old fashioned hospitals. Later in the day I was bent double like a giraffe (due to lack of knee bend) and scrubbed away with bleach - lovely job! Bleach and Dettol smells wafted through our clothes and hair - well my hair at least, Husband does not have too much!!!!