An apparatus for growing aquatic organisms in a controlled and compact environment, the apparatus comprising: a plurality of vertically stacked modules , each module configured to contain the aquatic organisms and a liquid growth medium, the plurality of vertically stacked modules comprising a first module comprising: an inlet , an outlet , a floor, and a first valve in fluid communication with the outlet , the first valve comprising: a first baffle extending from the floor of the first module and defining at least a portion of the outlet , and a second baffle disposed between the first baffle and the inlet and comprising a bottom end separated vertically from the floor of the first module ; and a first vertical raceway in fluid communication with the first valve and the plurality of vertically stacked modules ; wherein the first valve defines a flow path for the liquid growth medium underneath the second baffle, over the first baffle, and into the outlet ; and wherein the height and location of the baffles of the first valve are configured to enable (i) flow of a predetermined volume of the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a first flow state, and (ii) flow of a predetermined volume of the aquatic organisms with the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a second flow state. an inlet , an outlet , a floor, and a first valve in fluid communication with the outlet , the first valve comprising: a first baffle extending from the floor of the first module and defining at least a portion of the outlet , and a second baffle disposed between the first baffle and the inlet and comprising a bottom end separated vertically from the floor of the first module ; and a first vertical raceway in fluid communication with the first valve and the plurality of vertically stacked modules ; wherein the first valve defines a flow path for the liquid growth medium underneath the second baffle, over the first baffle, and into the outlet ; and wherein the height and location of the baffles of the first valve are configured to enable (i) flow of a predetermined volume of the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a first flow state, and (ii) flow of a predetermined volume of the aquatic organisms with the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a second flow state. wherein the first valve defines a flow path for the liquid growth medium underneath the second baffle, over the first baffle, and into the outlet ; and wherein the height and location of the baffles of the first valve are configured to enable (i) flow of a predetermined volume of the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a first flow state, and (ii) flow of a predetermined volume of the aquatic organisms with the liquid growth medium into the first vertical raceway and from the first module to a lower module disposed below the first module in a second flow state. <EOS>