We have some grass carp but I know they aren't Tilapia. What do they do different? We are trying to get ground support to end all fertilizer use in the neighborhood. Some people are addicted to the stuff though so it may be an issue for them.
Grass carp are not your choice for filamentous algae. They are only effective on rooted plants and have preferences even then, and are not immediately effective.
As long as you have even a few people applying lawn fertilizers you will be dealing with this forever. It doesn't take much.
