January 23, 2025 2 min read
Cyanobacteria or blue-green algae (BGA) appear as dark green slime. This algae begins as translucent sheets, often along the substrate and hugging poorly growing plants. It can form filaments that drift in the current. It is often caused by a combination of deteriorating plants, excess organic waste at substrate level, low oxygen levels and low nitrates. BGA is actually a photosynthetic bacterium that can fix gaseous nitrogen. In large quantities it smothers plants and plant growth can stall - leading to further problems.
Algae eaters often avoid this algae as it can be toxic.
A patch of cynobacteria / blue-green algae (BGA) on substrate, above.
Blue-Green algae appears as a slime across carpet plants above.
BGA on Crypts above.
Here are links to further reading on:
Click here for information on how to solve algae problems without algicides.
Click here for information on how to do proper water changes for a planted tank.
Click here for information on how to stabilize a new planted tank quickly.