The Oxidizer is by Arch Chemicals, the makers of Baquacil. And it wasn't a solid or liquid but, the consistancy of laundry powder. I had some definite success, where I broadcast it in, but it wasn't enough for the degree of my problem. But, at $5. a bag it's not bad if it works. Baquacil Ultra supposudly has a simular thing at $50.00. Will let you know what happens.