I want to kill off my Hydrilla, I currently have my 1 acre pond, depths of 5' to 12', covered in hydrilla. It is growing to the surface, even in the 12' depths. I want to kill off small sections at a time to control the lost of oxygen and do about 1/5th of an acre at a time, every 2 weeks. I don't understand how I could kill off only a small section with a spray herbicide? I would be more confident with granular herbicide. Thanks in advance!

I'd use a spray.

I tried using granular 2 4-D herbicides to clear one bank of my pond and it ended up killing about 90% of the weeds in the pond.

If you use sprays you can just kill the areas targeted. I used Polaris in a spray to keep the bank clear after it started to grow back.

See your other post about the Hydrilla for my answer.

esshup, I can't find your response that you mention?

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=40647&Number=527822#Post527822