Every life that carries out photosynthesis needs the basic building blocks of oxygen (O), carbon (C), nitrogen (N), water (H2O) and phosphorus (P). In order to give undesirable organisms such as filamentous or floating algae as little room as possible to grow, we have to remove one or more building blocks from the equation. Of course, water is essential in a swimming pond and oxygen, carbon and nitrogen are regularly present in our atmosphere and dissolve in the water without any effort on our part. The simplest approach to minimising filamentous or floating algae is to reduce the amount of phosphorus compounds in the water. This can be done, for example, in the filtration area, by aquatic plants growing in the pond or by adsorption units (see product group III - phosphate adsorbers). Under certain circumstances, it can still happen that the measures taken are not sufficient and a large amount of free phosphates are dissolved in the water. In this case, you should get ahead of the biology and chemically bind the free phosphates through the targeted use of so-called precipitants (see iron-III chloride solution (40%)) before the growth of the filamentous algae explodes.