I use tilapia I hatch and raise on the farm to control my filamentous algae and rooted plants in my biggest pond. No chemicals and weed cutting needed. I plant about a dozen broodfish into one of my smaller ponds in the spring and let them reproduce with no feeding needed. Then in the fall I seine out a few hundred of the offspring and put them in one of my basement DIY recirculating tanks and grow them out until spring. Then the cycle is started all over again with planting broodfish and I plant about 100 eight to twelve inch fish into the biggest pond and sell the excess to local pond owners.
One of the other benefits is they constantly spawn which provides forage for the bass along with available bluegills. Sure beats the expensive chemicals and labor needed otherwise.
No worries about them taking over the ponds as they die when water temps drop below 50 F.
They don't touch my bullrush so do cut it out late in the fall when it turns brown and dies and burn it. I like the bullrush along the shore but when it dies in the fall it builds up on the bottom which I don't want. Comes up nicely again in the spring.
A certain number of blue tilapia will control the filamentous algae but if you stock more they will control the rooted plants. I once had a couple hundred in a 1/10th acre pond and they left the bottom like a moonscape! Even went after the grass growing in the shallows!