Green water algae is one of the common issue in aquarium hobby and is faced atleast once in every hobbyist’s life. The reasons for any algae is due to the unbalance of the tank specially in planted aquarium where as freshwater tanks can also face similar issues. 


The primary reason for green water algae is:
1. The tank is exposed to sunlight.
2. The tank is not balanced (In case of planted aquarium).
3. The lights are on for too long.
4. The algae is introduced via external source (example fish plants bought from a source which has or had green algae in the aquarium).


Below is the image of green algae at its full bloom: Day 1 


Green Algae 1

There are many methods to get rid of green water algae, but the following method we found out to be the best:

Day 1

Step 1 : Switch off all light and cover the aquarium with any cloth or paper so that light does not enter. Make sure all other equipments are running.
Step 2 : Change 50-70% water.
Step 3 : Install a UV steriliser.


Day 3

Step 4: Remove the cloth and change 50% water. Let the UV run until the green algae disappears.


Green Algae 2

In the above image you can see the difference in 3 days.



1. Do not feed the fishes or look inside during this period.
2. If you still see algae then let it stay covered for another day or 2.


- Kshitij Gupta