Submersible fish farm

A method of operating a submersible fish rearing tank, wherein the submersible fish rearing tank includes

• an exterior enclosure made of a flexible material and forming a closed fish habitat,
• a utility transition element providing a transition for at least one of a water inlet, a water outlet, a gas outlet, an air inlet, and connections for instrumentation, the utility transition element being fixed to the flexible exterior enclosure,
• a first water pump unit adapted to pump water into the flexible exterior enclosure to provide a pressure inside the flexible exterior enclosure that exceeds a pressure acting on an outside of the flexible exterior enclosure,
• a water discharge column having a water discharge column outlet at a lower end of the water discharge column, through which internal water is discharged from an interior of the flexible exterior enclosure, the water discharge column outlet including a flow restriction or throttle which restricts an outlet flow of the internal water and thereby builds hydrodynamic pressure within the flexible exterior enclosure,
• a controller configured to control the first water pump unit and the flow restriction or throttle such that the hydrodynamic pressure built by the flow restriction or throttle together with the pressure provided by the first water pump unit keeps the flexible exterior enclosure inflated and stretched out so as to maximize an internal volume and maintain rigidity of the flexible exterior enclosure, and so as to maintain a pressure inside the flexible exterior enclosure that exceeds the pressure acting on the outside of the flexible exterior enclosure, and
• a ballast and an adjustable buoyancy element configured to orient and maintain a buoyancy of the submersible fish rearing tank, the method comprising:
• controlling the flow restriction or throttle in coordination with the first water pump unit to maintain one of a substantially constant pressure and a constant flow inside the flexible exterior enclosure while changing one of a waterflow through the first water pump unit and the flow restriction or throttle.

A method of operating a submersible fish rearing tank, wherein the submersible fish rearing tank includes

• an exterior enclosure made of a flexible material and forming a closed fish habitat,
• a utility transition element providing a transition for at least one of a water inlet, a water outlet, a gas outlet, an air inlet, and connections for instrumentation, the utility transition element being fixed to the flexible exterior enclosure,
• a first water pump unit adapted to pump water into the flexible exterior enclosure to provide a pressure inside the flexible exterior enclosure that exceeds a pressure acting on an outside of the flexible exterior enclosure,
• a water discharge column having a water discharge column outlet at a lower end of the water discharge column, through which internal water is discharged from an interior of the flexible exterior enclosure, the water discharge column outlet including a flow restriction or throttle which restricts an outlet flow of the internal water and thereby builds hydrodynamic pressure within the flexible exterior enclosure, and
• a ballast and an adjustable buoyancy element configured to orient and maintain a buoyancy of the submersible fish rearing tank, the method comprising:
• controlling the flow restriction or throttle in coordination with the first water pump unit to maintain one of a substantially constant pressure and a constant flow inside the flexible exterior enclosure while manually changing one of a waterflow through the first water pump unit and a waterflow through the flow restriction or throttle, such that the hydrodynamic pressure built by the flow restriction or throttle together with the pressure provided by the first water pump unit keeps the flexible exterior enclosure inflated and stretched out so as to maximize an internal volume and maintain rigidity of the flexible exterior enclosure, and so as to maintain a pressure inside the flexible exterior enclosure that exceeds the pressure acting on the outside of the flexible exterior enclosure.