Green Water or Surface Algae

What this symptom may mean

Nutrients, sunlight, warmth, stable water and insufficient circulation can support algae. Colour alone does not identify the organism.

Information and testing priorities

Responsible treatment pathway

Urgency

Prompt where water serves people or animals; urgent if harmful cyanobacteria are suspected.

What to send Puroxi

Important technical notice

Possible causes are not a diagnosis. Do not use this page to declare water safe, prescribe a chemical dose or delay emergency, health, veterinary or regulatory action. Testing and site-specific review are required.