Bermuda banish duckweed is the solution if your pond is having problems with duckweedr duckweed is a small aquatic flowering plant that floats on the surface of your ponjd water giving it an apparently continuous green layer surfacer although good for ponds in small blooms as it helps with nitrate removal a large bloom can effectively block out sunlight and deprive fish of oxygenr this treatment helps to quickly break down the duckweed in a manner which is safe to wildlife and fishr treats