What is the best treatment green pond weed? It's like green cottonwood.
Blanket weed is what you have. It's difficult to get rid of and Koi will not eat it. You can add barley straw bales to help get rid of it. Microbe-Lift PL works too and won't hurt your fish or plants. I have also dyed a pond black, waited three months and the blanket weed was gone. If you feed your fish, you are also feeding the algae. If you have koi, think about changing to goldfish, so you don't have to feed them.