Put some coontail in it and that green water will go away! Always does in my pond. Dang it. All of the people here would love to have water that look like that. Mine starts out that color every spring until the coontail sucks her in and leaves me with a clear aquarium! My pond is 2 1/2 acres. J/K about the coontail. Dont put it in there, it will eat the bloom but you can never get rid of the coontail. Sorry for the sarcastic post i couldnt help myself.