Aquaculture Pump System and Method

Abstract

A method of operating a variable speed pump in an aquaculture system including a culture tank that houses aquatic life. The method includes monitoring a dissolved oxygen level in the culture tank, determining a dissolved oxygen threshold based on current respiration requirements of the aquatic life in the culture tank, and comparing the dissolved oxygen level to the dissolved oxygen threshold. When the dissolved oxygen level is below the dissolved oxygen threshold, the method further includes increasing a speed of the variable speed pump until a flow rate through the culture tank that maintains the dissolved oxygen level at or above the dissolved oxygen threshold is reached. The method also includes updating the dissolved oxygen threshold based on new respiration requirements of the aquatic life as the aquatic life matures through its growth cycle.

1 . A method of operating a variable speed pump in an aquaculture system, the aquaculture system including a culture tank that houses aquatic life, the method comprising:
 monitoring a dissolved oxygen level in the culture tank;   determining a dissolved oxygen threshold based on current respiration requirements of the aquatic life in the culture tank;   comparing the dissolved oxygen level to the dissolved oxygen threshold;   when the dissolved oxygen level is below the dissolved oxygen threshold, increasing a speed of the variable speed pump until a flow rate through the culture tank that maintains the dissolved oxygen level at or above the dissolved oxygen threshold is reached; and   updating the dissolved oxygen threshold based on new respiration requirements of the aquatic life as the aquatic life matures through its growth cycle.   
     
     
         2 . The method of  claim 1  and further comprising monitoring at least one of ammonia, nitrite, nitrate, and solids removal. 
     
     
         3 . The method of  claim 2  and further comprising monitoring using sensors in a biofilter. 
     
     
         4 . The method of  claim 1  and further comprising increasing oxygen flow into the culture tank when the dissolved oxygen level is below the dissolved oxygen threshold. 
     
     
         5 . The method of  claim 4  and further comprising remotely operating a solenoid valve in order to increase the oxygen flow into the culture tank. 
     
     
         6 . The method of  claim 5  and further comprising providing two-way communication between the variable speed pump and the solenoid valve. 
     
     
         7 . The method of  claim 1  and further comprising using a flow control algorithm to operate the variable speed pump to maintain the flow rate. 
     
     
         8 . The method of  claim 1  and further comprising determining when to feed the fish based on the dissolved oxygen level. 
     
     
         9 . A recirculating aquaculture system comprising:
 a culture tank configured to house aquatic life;   a sensor configured to measure a dissolved oxygen level in the culture tank;   a variable speed pump configured to circulate water through the culture tank; and   a controller in communication with the sensor and the variable speed pump, the controller configured to:
 retrieve the dissolved oxygen level from the sensor; 
 determine a dissolved oxygen threshold based on current respiration requirements of the aquatic life in the culture tank; 
 compare the dissolved oxygen level to the dissolved oxygen threshold; 
 when the dissolved oxygen level is below the dissolved oxygen threshold, increase a speed of the variable speed pump until a flow rate through the culture tank that maintains the dissolved oxygen level at or above the dissolved oxygen threshold is reached; and 
 update the dissolved oxygen threshold based on new respiration requirements of the aquatic life as the aquatic life matures through its growth cycle. 
   
     
     
         10 . The recirculating aquaculture system of  claim 9 , wherein the controller includes a variable frequency drive. 
     
     
         11 . The recirculating aquaculture system of  claim 9  and further comprising an oxygen cone in fluid communication with the culture tank'through a solenoid valve 
     
     
         12 . The recirculating aquaculture system of  claim 11 , wherein the controller is further configured to operate the solenoid valve to increase oxygen flow into the culture tank when the dissolved oxygen threshold is below the dissolved oxygen level. 
     
     
         13 . The recirculating aquaculture system of  claim 9  and further comprising a biofilter in fluid communication with the culture tank and the variable speed pump. 
     
     
         14 . The recirculating aquaculture system of  claim 9 , wherein the controller includes a user interface, and the controller is configured to change the speed of the variable speed pump based on user input from the user interface. 
     
     
         15 . The recirculating aquaculture system of  claim 9 , wherein the controller is integrated into the variable speed pump. 
     
     
         16 . The recirculating aquaculture system of  claim 9 , wherein the controller is configured to determine at least one condition for feeding the aquatic life in the culture tank from the dissolved oxygen level measured by the sensor. 
     
     
         17 . The recirculating aquaculture system of  claim 9 , wherein the controller is an on-board controller adjacent to the variable speed pump. 
     
     
         18 . The recirculating aquaculture system of  claim 9  and further comprising a second sensor configured to measure one of ammonia, nitrite, nitrate, and solids removal. 
     
     
         19 . The recirculating aquaculture system of  claim 9 , wherein the controller is configured to use a flow control algorithm to operate the variable speed pump to maintain the flow rate. 
     
     
         20 . The recirculating aquaculture system of  claim 9 , wherein the variable speed pump includes multiple variable speed pumps and the controller is configured to operate the variable speed pumps in a cascading manner.