As long as there are ponds, there has always been one big “enemy”: blanked weed (or filamentous algae)! No problem for the fish and the water, algae also produce oxygen in the water and can be a form of food for fish. But we don’t like green water and don’t want blanked weed! No wonder that anti-algae agents/products like UV-C units and water treatment agents are very popular. Green algae (green water) have been successfully combated with UV-C lamps for over 30 years, but the filamentous algae in the pond are of course not affected. Fortunately, there are sufficient means on the market to fight these (sometimes metre-long) green strings. There is however one big problem… they always come back!
Cause of the problem
The cause of this problem lies in the feed for the blanked weed; Phosphate. Algae are simple organisms, they only need sunlight and nutrition (phosphate) in contrast to, for example, our aquatic plants that need a full range of macro- and micro nutrients. This results in an excess of phosphate for which mother nature has a simple solution; algae. However, as soon as we kill blanket weed with agents, the cell structure of the algae breaks down and the phosphate returns to the water. This is why we have to keep repeating the use of these agents.