Weeds can be a very big problem when you are trying to get rid of them. You see them in gardens, in lawns, and in the water as well. Aquatic weeds are very resilient, and although you may break your back trying to get rid of them, they seem to come back without any problems, and just pulling them out is not enough.
There are many chemicals you can use as an aquatic weeds killer, however, it is also important to note that if you are thinking of using chemicals on a pond or a canal because it is a place where you love to go fishing and the weeds are giving your motorboat trouble, then chemicals may not actually be the best thing to use.
They may kill the fish or at least send it off somewhere else, so at the end of the process you do end up with a clean pond, however, there is no fish for you to catch either.
You can also try using plastic lining on the bottom of the pond to avoid weeds, however, this is something you will have to undertake only in very small areas and if you are constructing an artificial water body around your garden. This may not be a permanent solution to the problem and you may have to repeat the process again.
Another way of handling a weed is to introduce a kind of fish that loves to eat aquatic plants and that multiplies very fast and which in the United States is called Grass Carp. This kind of fish likes to eat most of the weeds and if introduced in a pond of a large water area, then perhaps this could be a very good way of getting rid of aquatic weeds.