Aquarium preparation for controlling green algae in aquaria, which in favourable conditions can turn into heavy algal infestation. Excessive algal growth inhibits the development of other plants and may destroy them completely in time. Hence controlling algae, however difficult, is essential. If water in the aquarium is not only hard but also contains a high concentration of nitrogen and phosphorus compounds, it is subject to algae infestation. To monitor those parameters, we recommend Tropical tests.