Lebende Erde spülen

Just give plain water for the last 7-10 days before harvest, nothing else.

If your not adding anything and just watering because your using an organic "Super Soil" There is not much you can do in terms of flushing. Flushing is what @B_dawg does, water only for the last phase of growth. It is done with added nutrients since most of them are salt based and buildup in the medium. Adding only water for the last bit removes this buildup and ensures the final bud's don't have excess amounts in them when your drying. Happy Growing

I grow organically with slow release dry amendments. I Dont flush in the sense of runoff but i time the last feed about 3 weeks from harvest. Then use just phd water til the end.