This guide is written as an operating framework. Exact limits still depend on the organism, system volume, equipment and local rules.
Identify the growth form
Hair algae, diatoms, cyanobacteria, dinoflagellates and black beard algae need different responses.
Review recent changes
New lighting, disturbed substrate, dead livestock, overfeeding, depleted nutrients or altered flow can shift the system.
Remove biomass first
Manual removal exports nutrients and makes the underlying pattern visible.
Correct the system gradually
Balance light, nutrients, flow, filtration and grazing. Extreme nutrient stripping can create a different instability.
Track recurrence
A photograph and dated maintenance record reveal whether the response worked or merely hid the problem for a week.
Research and review
This is original AquaNexus writing. It does not reproduce third-party articles, tables, photographs or databases. Species-specific legal and husbandry claims must be checked against current authoritative sources before publication as final guidance.