This stuff is amazing. My pond was so green, I couldn't even see my fish. I put in the first treatment of the barley straw extract and a week later, my pond was completely clear. I could see to the bottom! I have a small pond, so the bales of barley straw were too big. With the extract, I can measure out just the right amount. It's so easy. You just pour it in the pond and you're done. And the fact that it's all natural and eco-friendly is very important to me. I don't want to use harsh chemicals. This way I know it's completely safe for the fish, the plants and pets who might take a drink sometimes. This bottle will last a very long time, too, because I only have to use a small dose each time.