Moss and dirt on reddish stones - Cleaning

Hello knowledgeable ones,

during our conversion campaign for the summer, we noticed that our reddish stones in the yard are full of moss and dirt.
Therefore, my question now is how and especially with which tool and possibly which chemicals you would proceed? Afterwards, apply any kind of protection?

asks Sylvia

I assume concrete stones stained red on the surface?

I assume these are concrete pavers colored red on the surface?

These are the stones, only they usually have a distinct red hue. They are supposed to get it back again ;-)

With chemicals, then a moss and green growth remover + scrub vigorously.
With less chemicals, then warm soda solution + scrub vigorously.
However, I think your stones are bleached. The red tone will always decrease...

I think so too. The concrete paving will only be colored 2 cm on top - the color will eventually fade. Mossed over actually looks a bit different :cool: If you have green deposits, spray them with Algen-Ex and treat/rinse off according to instructions. I wouldn't treat these stones with high pressure, as it makes the surface even more porous than it already is. How old is the paving?

We do not know that for sure. We will probably try it with Algenex. Thank you