We have a 1/2 acre pond with LMB, BG and CC. Aerated well water is added almost everyday. Here is the problem:

Floating FA covering about 1/3 of the surface. Some duckweed as well.
A variety of pondweed (chara, sago, maybe milfoil and hydrilla) covering about 1/2 of the bottom.

Water is very clear. We tried mechanical removal of the weeds but they came back right away.

Under the floating FA there is very little pondweed.

My questions:
Should I leave the FA to keep the pondweed down? If so, how much is too much before it needs to be removed?
Chemically treat the pondweeds (not sure what to use since there are so many varities present)?

Here are a couple pictures.
[img]http://www.photodump.com/viewer/tecman/Weedscloseup.html[/img] [img]http://www.photodump.com/viewer/tecman/Weedsoverview.html[/img]