I found this in the "product" section. Someone was asking about sonar.

"I would be very careful at eliminating a pond full of weeds (80%-90% coverage) in the warm water of summer. A massive weed kill will cause a strong reduction of dissolved oxygen which may result in a fish kill. Several factors such as temperature, amount of sunshine, amount of phytoplankton, presence of lake dyes and average pond depth will come into play here."

It's a little late now. But something to think about in the future.