Visible Symptoms
Pond water abruptly changes from green/brown to muddy gray or foam-covered clear; Secchi disk visibility increases from 25 cm to 60+ cm in 24 hours; dead algae scum accumulates on dikes.
Primary Causes
- Depletion of essential nutrients (Nitrogen, Phosphorus, Silica, or Carbon).
- Sudden heavy rainfall causing water stratification and thermal shock.
- Overgrowth of algae reaching biological carrying capacity and collapsing simultaneously.