The water net (genus Hydrodictyon) is a taxon of green algae of the family Hydrodictyaceae. Hydrodictyon like clean, eutrophic water and has become a pest in New Zealand, where it has been recently introduced. The name water net comes from the (usually pentagonal or hexagonal) mesh structure of their colonies, which can extend several decimeters.

The water net (genus Hydrodictyon) is a taxon of green algae of the family Hydrodictyaceae. Hydrodictyon like clean, eutrophic water and has become a pest in New Zealand, where it has been recently introduced. The name water net comes from the (usually pentagonal or hexagonal) mesh structure of their colonies, which can extend several decimeters.