Pond Boss Forums GENERAL QUESTIONS Water chemistry Phosphorus and forest fire?

It could be.

If you want to kill the EWM in the ponds for possibly up to 2-3 years treat the ponds when the water temp is 55°-60° with a 10 PB dose of Fluridone - Sonar AS or similar product. It will take up to 45 days for the EWM to die, but it will stay dead and the only way you will get more is if some of the seeds in the bottom of the pond germinate. Do that treatment every few years and you will eradicate it from the pond, and at that low dose, the native plants will survive.