Two years ago I started studying the clays here in the USA. After a month or so of chasing information down I ran up on Gene and Koi Clay. Gene had done even more research than I had and had found the best mine in the US for our use. The price of koi clay was reasonable, and I have been very pleased with the results. I would not keep koi without it. It dissolves very easy as it is milled to a very fine power and dissolves very easy into water. I like the size of the containers as it is just right for a season!! After I started using it my wife sounded like a Tide commercial. The whites were much whiter, and the reds were much redder on our fish, and the water sparkled. Koi Clay is easy to use. I dump a handful into a 5-gal bucket, hit it with a hose, stir it up with my hand and dump it into my pond late in the evening. Water has that sparkling look of white water the next morning. Just wanted to tell the world of what adding Koi Clay has done for my sick pond & fish! Griff Thomasson - 2004