Green Algae
Cladophora
Cladophora spp.
A stubborn branching green algae that forms rigid wiry tufts and is notoriously difficult to eradicate once established.
Quick facts
- Category
- Green Algae
- Organism group
- Green Algae
- Growth form
- Tuft
- Primary color
- Dark Green
- Secondary color
- Green
- Attachment
- Strong
- Removal difficulty
- Hard
Identification
Short, rigid, branching green filaments that form dense clumps rather than soft loose strands.
- Growth form: Tuft
- Primary color: Dark Green
- Secondary color: Green
Looks like: Unlike ordinary thread algae, Cladophora feels wiry, branches visibly, and is often described as tougher and less appetizing to algae eaters.
Where it appears
Typical affected areas
- On Plants
- On Hardscape
- On Substrate
Common contexts
- Too Much Light
- Nutrient Imbalance
Causes
Often arrives hidden on plants or hardscape and then persists because it is tough, branching, and difficult to graze away.
Most common triggers
- Introduced On Contaminated Plants Or Décor
- Persistent Imbalance Under Strong Light
- Survives Well Once Established
Root cause note: Cladophora is one of the hobby’s most persistent green algae because fragments can spread and re-establish easily.
Nutrient relevance
Balance relevance: Medium
Related nutrient issues
- Persistent Imbalance
Better balance helps, but this algae often also requires aggressive physical removal of infected material.
Correction hint: Do not rely on nutrient corrections alone if branching tufts are already well established.
Treatment
Quick action: Remove infested material aggressively and do not leave loose fragments in the aquarium.
Hard manual removal and preventing fragment spread are central; this is one of the toughest green algae forms.
Manual removal: Pull entire tufts out carefully and consider discarding heavily affected décor or leaves if the outbreak is severe.
Difficulty: Hard
Prevention
Inspect new plants and hardscape carefully and keep outbreaks small before they spread through fragments.
This page is designed to help with visual identification first, then causes, treatment, and prevention. Actual algae pressure can vary depending on maintenance, livestock, plant mass, light, flow, and nutrient consistency.