You have to determine exactly what you have before a treatment can be recommended. Muskgrass is also called Chara. Bladderwort is not muskgrass. The treatment methods for Chara and Bladderwort are different. There are other plants that have yellow flowers.

Try looking here and see if what you have is listed.

https://aquaplant.tamu.edu/plant-identification/

www.hoosierpondpros.com

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).