Pond Renovation

Introduction   |   What is Rotenone?   |   Preparing the Pond   |  
 Applying Rotenone   |   Restocking the Pond

How to Apply Rotenone

Rotenone is available in a wettable powder or a liquid formulation. Liquids are easier to get into solution and are more reliable for total fish kills. The liquid formulations typically contain 5 percent rotenone, although some contain 2.5 or 7 percent.

Treatment rates for a complete kill vary between 0.1 and 3 ppm rotenone, depending on the objective of the pond renovation and the species present. All formulations must be diluted with water and evenly distributed throughout the water column. You can spray the chemical over the pond surface or drip it into the prop wash of an outboard motor. The key is to have an even distribution; otherwise, fish may find "safe" areas and not be killed. Application in a random "S" pattern throughout the pond maximizes coverage.

The best time to eradicate fish from a pond for restocking is late summer or early fall. Water temperatures are at their highest at this time, and the weather is usually dry, allowing easy draining. Killing the fish at this time reduces the time between the kill and the restocking, which minimizes the chance the pond will be contaminated by unwanted fish before restocking. This is an important consideration, since letting in unwanted species can defeat the purpose for the renovation.

If you drain the pond, it is critical to poison all remaining puddles to kill any fish there. Many small fish can survive in these pools, puddles, or stump holes for a long time. You must kill all fish to have a successful renovation. Otherwise, these surviving fish can contaminate the new fish population, and the renovation will have been for nothing.