Away has very good geranium flower patches of (from) concrete flagstones

In my wet geraniums had left on (in) the light cast stone slabs my patio brown spots. Neither the use of Kärcher even the cleaner of a competitor brought, even with repeated use, a visible success.
When Lithofin MN Outdoor Cleaner was different. As early as the first application most stains were gone, the other spots were gone after the second application and only so weak that I have omitted a third application. Discolouration of the concrete blocks, I could not detect any. The agent was applied according to the instructions on the bottle.

For stains on geraniums (in) cast stone would recommend the middle in good conscience.