How to Grow Algae in a Tank

Algae are simple organisms that contain chlorophyll and normally grow in aquatic conditions. Algae are found in places like rivers, lakes and streams, but are also commonly found inside home aquariums. A little algae growth is normal and can be beneficial to the overall health of a fish tank. Large amounts of algae can have negative effects on a fish tank. Too much algae makes for an unsightly appearance and can create stress on fish living in the aquarium.

Things You'll Need

  • Direct sunlight
  • Artificial lighting
  • Fish food
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Instructions

    • 1

      Place a tank full of water where it can get direct sunlight to quickly grow algae. Alternatively, use artificial light if only minor algae growth is desired. Artificial lighting includes any lightbulbs or lighting system that shines onto the water of your tank. The higher the intensity of the lightbulb and the longer the light is on, the faster algae growth. For minor algae growth, use artificial lighting for no more than eight hours a day.

    • 2

      Create the proper nutrient levels in the water, including higher amounts of phosphorus and nitrogen. One of the easiest ways to increase nutrient levels is to overfeed fish with store-bought fish foods. As the uneaten food breaks down in the tank, nitrate and phosphorus levels increase, giving algae a chance to grow.

    • 3

      Avoid water changes to grow large amounts of algae. Small amounts of algae can grow in tanks where 10 to 15 percent of the water is changed each week. This amount of algae is normally healthy for aquariums.

    • 4

      Use live plants and algae-eating fish in your aquarium if you want to keep your algae growth minimal. Live plants use the same nutrients as algae and some species of fish ̵2; such as Black Molly or Siamese Algae Eaters ̵2; feed on algae and can help keep your aquarium clean. Cleaning your tank when algae starts growing on walls and in other places will also keep algae growth to a minimum.