Algae occurs wherever water is found – even if the water is only a temporary presence. It does not become visible until it gets out of control, and may cause problems. Algae can proliferate very quickly in favourable conditions, grow over everything else and negatively impact the water parameters. To prevent algae, the first thing you need to do is stop conditions from developing that encourage algae growth:
1) Avoid and/or limit intense light from the sun or lighting by choosing a suitable, shaded location for the pond. Another useful tip is to include floating plants such as water lilies that also reduce the incidence of sunlight.
2) Reduce high nitrate and phosphate levels or prevent high levels from occurring using fast-growing pond and marsh plants. The plants absorb nitrate and phosphate as nutrients before excess nitrate and phosphate enable algae to grow.
3) Remove built-up sediment and other dead organic material from the water at an early stage.