We moved into this house almost 3 years ago now, one of the first things we did was install two water tanks, we were in the middle of a drought at that time. Being an older house that had never had water tanks the down pipes were not sealed, they would normally just allow the water to flow down and into the storm water system. Installing the tanks meant the down pipes had joins below the line of the tank inlet and would therefore need to be sealed for the system to function.
I ran around and did this ad hoc and some ended up sealed better than others, the join in question has a slow leak. It developed from a harmless dribble, to a little green slime, to what I found today to be a micro garden clinging to this PVC down pipe! Pretty cool what a little neglect can allow to blossom sometimes, it’s going to be hard to bring myself to clean this off to seal up the pipe properly…
I’m guessing they are weeds, but I think they have earnt their place on that pipe the hard way.
Sludge and slime, still impressive.