How to Determine How Plants Affect the Water Quality of a Goldfish Tank

Aquatic plants are both attractive and functional in an aquarium. Aquatic plants grow in the presence of light and receive nutrients from metabolic waste that they remove from the water. Once established in the aquarium, aquatic plants assist to create balanced water conditions. Aquarium plants are a valuable addition to a freshwater tank because they remove carbon dioxide and produce oxygen. Plants also remove nitrates and phosphates from aquarium water. Aquarists will be able to see the positive results after adding plants to their aquarium and can test the water quality to confirm what they see.

Things You'll Need

  • Fresh water aquarium
  • A variety of aquatic plants
  • Oxygen test kit
  • Carbon dioxide test kit
  • Phosphate test kit
  • Nitrate test kit
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Instructions

    • 1

      Use an oxygen test kit to measure the amount of available oxygen in the water. Aquatic plants give off oxygen, which is essential to the well being of the goldfish. Oxygen also enters the aquarium water via the surface, but oxygen levels will be higher in a well and densely planted tank.

    • 2

      Use a carbon dioxide test kit to measure the amount of carbon dioxide in the water. Aquatic plants use carbon dioxide, which the goldfish give off during the process of respiration. Carbon dioxide is toxic in large amounts and as it builds up in the water, the goldfish are unable to release it from their blood.

    • 3

      Use a phosphate test kit to measure the amount of phosphate in the water. There will be very little phosphate in a well planted aquarium, as plants will remove it. Phosphates contribute towards the growth of nuisance algae, which will be minimal in an aquarium with established plants.

    • 4

      Use a nitrate (NO3-) test kit to measure the amount of nitrate in the water. Aquatic plants remove nitrate from aquarium water and the test kit will show very low amounts.

    • 5

      Look out for signs of nuisance algae in the tank. Plants compete with unwanted algae for light and nutrients in the water. In a densely planted aquarium, the aquatic plants will compete with unwanted algae for nutrients and the aquarium will have a clean and well looked-after appearance.

    • 6

      Observe your fish and check their colors. Aquarium fish exhibit bright colors when the water quality is optimal. Aquatic plants assist to keep aquarium water in a healthy and balanced condition, and vividly colored fish will testify that the water is in optimal condition.