I think you have FA and water primrose.
Agreed.
Water with nutrients in it will grow "weeds". Excess nutrients will also grow FA along with the "weeds".
Consider doing an alum/hydrated lime treatment to lock up some of the excess nutrients.
Or, rake out a lot of the plants/algae and get it away from the pond so that when it breaks down it doesn't revert back to nutrients.
BUT, with the goats and horses having access to the pond, they will contribute to the nutrient load.
The choices are:
1) Limit and manage the nutrient loading of the pond.
or
2) Manually remove plants and algae if they become obnoxious
or
3) Introduce Tilapia to consume the algae, and get a stocking permit from TP&W to introduce Triploid Grass Carp, although they aren't knows to be very fond of Primrose.
or
4) Control it with chemicals.
An aeration system will help, but it isn't a magic bullet that will take care of the problem by itself.
