Causes For Green Water In Aquariums And How To Fix It

You know when you notice that unpleasantly green water from time to time in your fish tank. This is due to a bloom of algae. Algae is some type of aquatic plant life and did you know that over eight-thousand species presently exist on earth? Just like other plant species, it uses photosynthesis of light to generate energy and to grow. The most common forms of algae that you’ll notice in many fish aquariums are freshwater green algae. Many fish aquariums have some type of algae present most of the time, and as a matter of fact, algae can be a useful food source for snails and other types of aquatic creatures that you have in your aquarium setting. The problem usually starts once a bloom is getting out of control and starts turning the tank water opaque and murky. The green color happens due to the quantity of microscopic algae becoming so elevated that it lowers the transparency of the tank water. In severe instance, the water might become so green that you can’t even see the fish.

What Are The Causes?

  • Excess light – particularly when the aquarium is exposed to direct sunlight. Like other plants, algae also photosynthesize light. Aquariums that are exposed to direct sunlight is more susceptible to algae blooms.
  • Too many fish in the tank – which could result in many organic wastes that offer nutrients to aquatic plants.
  • Overfeeding – food particles that are left uneaten starts becoming nutrients which are used by algae for growth.

When your tank has green water, it is generally the result of either a substantial amount of excess light (in particular direct sunlight) or a significant water quality issue. Even though, it may be looking terrible, it is not dangerous to fish. You can visit for more information about aquarium-related topics and products.

What Are The Cures?

  • Start by blocking out light sources entirely. This will help with shutting down the photosynthesis which is needed for algae to grow.
  • Think about installing a micron or diatomic filtration system to remove suspended algae in the tank.
  • You can introduce daphnia to the aquarium. They are tiny crustaceans that snack on algae, and they can subsequently be eaten by the fish.
  • You can introduce shrimp or snails to the aquarium.

Regular water changes can also assist in reducing green water temporarily, however, will not eliminate the issue or keep algae from returning, unless you’ve addressed the underlying causes.

Warning: The water aggregators that you can buy from pet stores that claim to clump suspended algae and get rid of it, is not an effective remedy for green water.

How To Prevent Water From Turning Green

  • Frequent water changes
  • Cleaning your aquarium frequently.
  • Using a UV filter.
  • Prevent direct sunlight to the aquarium.
  • Not overfeeding the fish.
  • Avoid overstocking your aquarium.

    As with other aquarium issues, keeping the tank spotless and doing frequent water changes is among the best defences against algae blooms that are out of control. Quick attention to algae growth can prevent more severe issues in the aquarium.