Would Tilapia help?
I can't help you because I'm just learning about this stuff. Our pond is new so has not had the time to develop problems like you have but we are already getting FA.
The reason I bring up Tilapia is in some of my reading they are claimed to be very good vegetative eaters. One ad claims that they will do almost everything except walk the dog, but I figured they might be overselling a bit.
I know there are people on this forum that have experience with them and can suggest if they would be beneficial.
