Tips for Preventing Algae
Aeration is critical to help keep the water oxygenated year-round. It will also keep the good anaerobic bacteria active during the summertime to break down the nutrients and debris. You can use a fountain, waterfall, or an aerator to keep the surface water constantly moving.
There are three types of filtration systems: mechanical, biological, and UV clarifiers. Mechanical filtration removes smaller debris by pushing the water through a filtration pad. Biological filters utilize good bacteria to help break down nutrients and debris. UV clarifiers help to break down the algae at a microscopic level using ultraviolet (UV) light.
Many pond plants are dual-purpose decorations. Floating plants like lilies and water lettuce create shade and prevent algae from getting the sunlight it needs. Marginals like iris and pickerelweed help soak up the extra nutrients in the water.
Pond nets can help leaves from entering your pond. You can also manually scoop out leaves and other debris daily.
Water quality tests
Checking water quality will help you detect any issues before they get out of control. You can check for excess nutrients like phosphates or nitrates and see how your oxygen levels are. You need to find the source of the excess nutrients so the algae don't keep coming back after treatments.
Too much direct sunlight can heat the water, causing the water temperature to rise and the oxygen levels to drop. Also, algae need direct sunlight to photosynthesize. You can create more by adding the right types of plants, floating plants on the surface, or taller perimeter plants to block the sunlight. Artificial plants like the Floating Lilies or adding a treatment like Pond Tint also help to create shade. Read more about adding shade.
Preventative water treatments like beneficial bacteria, sludge remover, and pond tint can help prevent algae from taking over your pond.