VDH watersystems is specialist on watertreatment with copper and silver ionisation.

Free copper (CU++) and silver ions (Ag+) have a toxic effect on micro-organisms even in relatively low concentrations. They have a highly fungicidal, bactericidal and algaecidel effect. Medical studies describe silver ions a catalyst that disable the enzymes that microorganisms depend on to "breathe".
In the presence of air (oxygen in water). metallic silver forms silver oxide, which also has a bactericidal effect due to its adequate solubility. The destruction of viruses, bacteria, moulds, spores and fungi through contact with silver objects is termed the oligodynamic effect. To primitive life forms, oligodynamic silver is as toxic as the most powerful chemical disinfectants. This, coupled with its relative harmlessness to animate life (i.e. mammals), gives olygodinamic silver great potential disinfectant.

Special for greenhouses the Multi micro element controller is developed , copper and silver ions can be adjust in to the waterstream. 

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