It was green once so green,

to this concentrate was used. The challenge consisted of:
1. Paved yard area (150 square meters), completely covered with light green covering.
2nd terrace (40 sqm), gray white granite slabs, although gekärchert, but in the pores and depressions were black green 'nests' get stubborn.
3. Klinkermauer (10 sqm), completely covered with light green covering.
4. way with old concrete slabs (10 square meters), although gekärchert, but the plates remained unsightly and 'grubby'.

The 2 liters of concentrate I have 1:10, so I was able to fill four times the hump syringe with the 22 liters. With this amount I got for my 210 square meter closely, although I had a little thinner einnebeln the yard area because it was close.

The results after one week activity time:
1. The Hofpflaster wonderfully clean (by the way after 24 h.).
2. Granite plates a little cleaner, but deep seated Schiet stays inside.
3. The clinker looks like freshly bricked and re-grouting.
4. The old way is old; no effect on the old exposed aggregate concrete, the panels are however already 35 years under old trees.

Test default I have been a strong spray on moss in a lawn, here had no effect.
Speaking of lawns: Semi grass has been no yellow (!). So a responsibility I can not give;)

My tight Conclusion: In about 10 for 22l legally effective solution to do nothing wrong, but you have to focus on more stubborn cases probably far more, and then the fun can be quite costly.

For 'fresh' green growth anyway my best recommendation!