Disclosed is an alkali aqueous flocculating agent based on an alkali aqueous salt clay extract containing dissolved silicate and aluminate, in addition to alkali chloride whereby for an aluminate (1) content by weight expressed as Al(OH)3, 1.) approximately 2 to 3 parts by weight of silicate expressed as SiO2 are provided and 2) at least approximately (10) parts by weight, especially at least (20) parts by weight of alkali chloride are provided, in addition to a flocculating and a sedimentation agent in the form of an acidic and alkali-extracted salt clay. The invention further relates to a method for the production of said flocculating and sedimentation agents which can be used advantageously in swimming baths, for the treatment of drinking water, industrial water, grey water and waste water in sewage treatment plants as auxiliary agents for absorption, sedimentation and filtration. Said agents can also be used to reduce the amount of harmful substances and to embellish water in swimming pools, ponds and biotopes. The respective flocculating agent is more particularly used by means of dosing systems. One particular advantage of the invention is that the agent is obtained from a natural product and can be used in swimming pools and water biotopes without any harmful side effects.