Hydrochloric acid, 1 L

Brand - -. Usage - Diluted hydrochloric acid at a ratio of 1:3 with water should be applied to the surface to be cleaned with a brush and allowed to react (until no more bubbles are released). When diluting, carefully pour the acid into the water! Scrub off cement residues or moss deposits with a stiff brush and rinse the surface thoroughly. If necessary, clean again.