David Hogg is a dickweed, not a Hoggweed.
And a pillow-biter.
Tsk, tsk, G.W.!
I am sure you meant Duckweed and not that other stuff!
Removing scum from your pond.
https://pondwiki.com/duckweed-control-in-pond/ :)
(Barley Straw helps I understand!)