Chara also known as muskgrass is an algae instead of a rooted plant life.  It can be controlled with Cutrine Plus Granular a chelated copper form that is an algaecide instead of a herbicide.  Treatments for Chara are less expensive than other herbicide treatments.  Make sure of your vegetation before you treat.  It could save you money.  Chara can be treated with 30lbs of product for 1/2 acre.  Chara is a type of algae that grows on the bottom of ponds and lakes. It can cause problems such as blocking sunlight, interfering with recreation, and altering the ecosystem. It is hard to control because it can re-grow from spores and fragments and is resistant to some treatments. It can be controlled with various methods grass carp or physical removal can be considered.