Abstract: A water treatment unit includes a mixing chamber surrounding the upper end of a riser containing an impeller, Water can be moved from a body of water up through the riser, and out through laterally directed openings into the chamber adjacent to an air inlet, The water moving out the laterally directed openings of the stand pipe, mixes with air drawn in through the air inlet to oxygenate the water, and the oxygenated water exits the chamber into the body of water through one or more water outlets in the lower portion of the chamber due to the head developed by the inflow of water into the chamber. The outward flow of water from the chamber can cause a toroidal or other desired flow of water within the body of water surrounding the water treatment apparatus.

Abstract: A water treatment unit includes a mixing chamber surrounding the upper end of a riser containing an impeller. Water can be moved from a body of water up through the riser, and out through laterally directed openings into the chamber adjacent to an air inlet. The water moving out the laterally directed openings of the stand pipe, mixes with air drawn in through the air inlet to oxygenate the water, and the oxygenated water exits the chamber into the body of water through one or more water outlets in the lower portion of the chamber due to the head developed by the inflow of water into the chamber. The outward flow of water from the chamber can cause a toroidal or other desired flow of water within the body of water surrounding the water treatment apparatus.

Abstract: A recirculated marine aquaculture system for growing crustaceans within a body of water includes a wholly submerged chamber situated in the body of water having a filtering wall connecting the chamber floor and ceiling permitting water to flow from the water body into the first chamber while excluding particulate materials. A second chamber is situated above the first chamber having a plurality of water outlets below the body of water upper surface, and a top having an air inlet above the body of water upper surface. A stand pipe has an open lower end opening into the first chamber and a plurality of laterally directed openings into the top of the second chamber. An impeller coupled to the stand pipe moves filtered water from the first chamber through the laterally directed openings into the second chamber adjacent to the air inlet, the water exiting the second chamber into the body of water through the plurality of water outlets after mixing with air drawn in through the air inlet.