Simple definition: Eutrophication is the buildup of excess nutrients in pond water, usually from fish waste or uneaten food, that fuels algae blooms.
Detailed Explanation
Excess nitrogen and phosphorus act as fertilizer for algae. A heavy bloom can look dramatic during the day, then crash and consume large amounts of oxygen overnight as it decomposes.
Why It Matters
Sudden algae die-offs after a bloom are a common cause of overnight fish kills, since decomposition strips oxygen from the water fast.
Practical Example
Overfeeding is one of the fastest ways to push a pond toward eutrophication, since uneaten food breaks down into the same nutrients as fish waste.
