Algae Treatment in Aquariums

Q: What are the most common types of algae?

Green algae, brown algae, filamentous algae, brush algae, or cyanobacteria (false algae). Each type has a different cause.

Q: Can CO₂ cause algae?

Yes, an excess of CO₂ or a poor balance can promote their appearance. Poorly distributed or unstable CO₂ diffusion is often the cause.

Why Do Algae Appear?

An imbalance between light, nutrients, and CO₂ can quickly lead to algae growth. Poor fertilization, excess food, or poorly managed lighting are the most common causes.

Main Types of Algae

Cyanobacteria: Not true algae, they look like a slimy green deposit at the bottom of your tank. You'll need an antibiotic to get rid of them. We suggest one below.
Green algae: Often caused by excess light or a lack of nitrates.
Brown algae: Common in new aquariums, caused by insufficient lighting.
Brush algae: Very persistent, often linked to poor CO₂ diffusion or water rich in phosphates.
Filamentous algae: Develop with excess light and an unbalanced PO4/NO3 ratio.
Green water: This water coloration is caused by a proliferation of suspended microalgae, often due to excess light and nutrients. It makes the water cloudy, even after water changes. The most effective treatment is using a UV sterilizer lamp for aquariums, which eliminates suspended algae without disturbing the tank's biological balance. Tip: run the UV lamp 4-5 days each month; never leave it on continuously for weeks, as it may harm the fish's immune system.

How to Treat Algae?

Here are possible actions depending on the algae type:

Correct water parameters (NO3, PO4, CO₂): follow our guide to test your parameters.
Reduce lighting or adjust its duration.
Add fast-growing plants to compete with algae.
Use an appropriate anti-algae treatment.

FAQ about Aquarium Algae

Why do I have algae in my aquarium?

Algae often appear due to an imbalance between light, nutrients (NO₃/PO₄), and CO₂.

What are the most common types of algae?

Green, brown, filamentous, brush algae, or cyanobacteria (false algae). Each type has a different cause.

How to effectively treat algae?

By adjusting water parameters, reducing lighting, and sometimes using specific anti-algae products depending on the type encountered.

Can CO₂ cause algae?

Yes, excess or poorly balanced CO₂ can promote algae growth. Poorly distributed or unstable CO₂ diffusion is often responsible.

Algae Treatment in Aquariums

Why Do Algae Appear?

Main Types of Algae

How to Treat Algae?

Recommended Products Against Aquarium Algae

Anti-cyanobacteria Aquarium Treatment

Generic Anti-Algae Treatment

UV Lamp Against Green Water

FAQ about Aquarium Algae

Why do I have algae in my aquarium?

What are the most common types of algae?

How to effectively treat algae?

Can CO₂ cause algae?