How to control Green water algae in a planted tank

This form of algae is also known as "green pea" soup. The water turns into a cloudy green colour.

Common Cause

The primary cause is excess ammonia coupled with strong light for extended periods. This may occur particularly in new tanks / planted tanks that are not biologically mature. It often results from over-feeding, high levels of livestock waste and/or plant decomposition. It is more common in very warm tanks (80f+).

Solutions

• Some mild cases disappear on their own as the tank matures
• Immediately lower light intensity (by increasing the distance of the light source from the tank or adding shades) and reduce lighting-period to 5 hours until problem disappears
• Mild cases can be cured by over-dosing Excel (which can hurt both livestock & plants) or by using Purigen as filtration media
• 4 - 5 day blackout for serious cases
• Use Diatom filters
• UV steriliser is a 100% cure for serious cases

For detailed steps on how to cycle a tank, click here.