A floating nitrification reactor for use in a treatment pond utilizes a mass of high surface area material which provides sites for bacterial treatment. Floatation devices are attached to the mass of high surface area material in order to float the material at neutral buoyancy while an isolator surrounds the material and isolates the material from the rest of the treatment pond. An aerator, located a distance below the mass of high surface area material, forces air and water through the material at a sufficient speed to allow treatment.