I have an exposed aggregate patio.
I don't use it much and it gets covered with thick moss.
I decided I'd clean it and seal the surface to prevent regrowth.
Two days later with a gas pressure washer, I've removed three
5-gallon buckets of moss. I also soaked it down with moss killer.
But there are still remnants I can't dislodge.
They're tiny black strands about half an inch long in clusters of
a few dozen or so. They're FIRMLY rooted in the concrete. The strands
are very strong, but not as strong as the roots. Just pulling on them
ain't gonna get them out.
I even tried burning them with a propane torch. They don't burn very well.
I'm not willing to pick them out individually with an Xacto Knife.