Patent ID: 7517460

Claim:
A method of treating a tank of water having film of ammonia oxidizing bacteria on wall and floor surfaces of the tank, the method including the steps of: (a) providing a flotation platform, an impeller, and a flexible draft hose with a main body and a bottom inlet arrangement supported on the tank floor, (b) depending an upper portion of the main body of said draft hose substantially vertically downwardly from the flotation platform, (c) extending a lower portion of the main body of said draft hose substantially radially outwardly of said upper portion to said inlet arrangement, (d) creating a flow pattern in the tank water outwardly of the flotation platform along the surface of the water, down the wall surfaces, inwardly across the surface of the tank floor to the bottom inlet arrangement of the draft hose, and up the draft hose back to the flotation platform, (e) directing said flow pattern to draw water adjacent the surface of the tank floor substantially radially inwardly along the tank floor toward a substantially vertical axis into said inlet arrangement and up through the main body of the draft hose to the flotation platform, and (f) selectively injecting at least one disinfectant into said inlet arrangement to enter the flow pattern of the water, contact, and kill the film of ammonia oxidizing bacteria on the surfaces of the walls and floor.