It all depends on your current water clarity/quality. It could increase your nutrient load to uncomfortable or even dangerous levels. As an ol' farm boy, I'm sure you understand about the consequences of over fertilization. The dying and dead plants increase the phytoplankton level of the water. Phyto emits oxygen during the day and consumes it at night or under cloudy conditions. If it consumes too much of the oxygen you have what we call a DO crash that makes things really tough on fish. In other words they suffocate.

How is your water quality now? Your visibility should, optimally, be between 18 and 24 inches. Make a sechi disk. That's no more than a white disk. I use the top of a white plastic bucket. Cut a hole in it and pass a string though the hole. Tie a weight onto the bottom and lower it into the pond. Measure the point at which it disappears.

To be careful, only do 1/3 or so of the pond at a time. That gives fish somewhere else to go.

Actually, herbicides usage can be a viscous cycle. You kill plants that create fertilizer that creates more plants.

You have to kill carefully and stay on top of the situation. Try to maintain about 20 to 25% plant cover for small fish to hide in.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP Grandpa