How to Create Phytoplankton

Phytoplankton is found in both freshwater and saltwater environments. This green algae is a nutrient-rich food source for many species of fish and seahorses. Pet owners can pay more than $20 per liter in some cases. However, growing phytoplankton is quite easy and can be a fun experiment to perform at home.

Things You'll Need

  • 2-gallon clear aquarium
  • Air pump
  • Air stone
  • Airline tubing
  • Fluorescent lamp (many aquarium lids have one built in)
  • 7-watt incandescent light bulb with standard threads
  • Miracle-Gro® Water Soluble All Purpose Plant Food
  • 1 gallon natural seawater
  • 3 gallons artificial seawater
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Instructions

    • 1

      Fill a 2-gallon aquarium with 1 gallon each of natural and artificial seawater.

    • 2

      Install the air stone and airline tubing in the aquarium, and connect the opposite end of the airline to the air pump. Turn on the air pump and verify that the air stone is functioning properly (air bubbles will be seen leaving the air stone). Leave the air pump on 24 hours a day.

    • 3

      Add approximately 1 tbsp. of Miracle-Gro® to the aquarium solution.

    • 4

      Install the 7-watt incandescent bulb in the fluorescent lamp (the lamp fixture installed in the aquarium lid). Place the lid securely on the aquarium with the light on. In cases where a separate lamp is being used as a light source, be sure to place the lamp near the aquarium at an angle where the light falls on the maximum amount of water possible. Leave the light running 24 hours a day.

    • 5

      Add 1 tbsp. of Miracle-Gro® to the aquarium every 2 days until the water becomes emerald green. This can take 1 to 2 weeks depending on the initial amount of phytoplankton in the natural seawater used to start the culture.

    • 6

      Remove approximately half of the water from the aquarium and replace it with 1 gallon of artificial seawater.

    • 7

      Wait approximately 3 days to 1 week or until the water has returned to an emerald green color, and then repeat Step 6. Once the water has again turned a deep emerald green, the phytoplankton is ready for use. This final stage can take up to 1 week to complete.