I've used liquid barley and it is fantastic, but very pricey. I also use barley straw in the biofalls, because it is free for us from a brother-in-law who is a farmer. Filled pantyhose and placed them in the bottom of the new lilly pond this year worked pretty good for a while, but before our pond show I did use liquid barley in both ponds. Remember it is not an instant thing it will take a while to work, but is great and all natural.