Proof of Concept: Automated Pump Control

While we gear up to put our Aquaponics system into full operation, some time needs to be devoted to the development of the automated control and monitor system.

As a brief update we have secured a modest aquarium and have stocked it with six goldfish in order to start the cycling process.  Typically it is necessary to place fish in the tank and to wait for the proliferation of certain bacteria.  This process can take a bit of time so we opted to remove gravel from the donor’s tank  in an effort to “salt” our system with bacteria.    We installed an automatic feeder and, until we have the pump system up and running, we installed an air stone for aeration.

Moving on.  A logical choice for system automation is to use an Arduino microcontroller.  Arduino boards are open-source and there is a plethora of development information available including circuit design and code.  Capable of both input and output tasks, the Arduino UNO will likely be used to control the ebb-and-flow pumps, to monitor temperature, and for system redundancy.  The idea is to connect a Hall-Effect flow meter in line with each of two submersible pumps.  One pump will be on at any given time, should it fail, the back up pump will immediately come online.  The plan is to use a flow-meter on each pump to send feedback to the controller, indicating that the pump is…pumping.  If the flow-meter attached to the active pump indicates that no water is being pumped, the controller will assume that the given pump has failed and will command the second pump online and will look for a corresponding signal from that flow-meter.

Left LED representing “Pump 1” ON

Right LED representing "Pump 2" as ON, switch makes Arduino Controller think "Pump1" has failed

As a proof-of-concept, a simple LED circuit was prototyped.  The LED on the left represents “Pump 1” and the LED on the right represents “Pump 2”.  The DPST microswitch is our pretend “pump failure”   Note that no flow-meters are included as we do not have these on-hand currently.  A simple program was written to prove the idea, albeit in a simplified manner.

Now comes the hard part, making a 5VDC microcontroller switch relays that ultimately control a 110VAC aquarium pump, all based off the readings coming from in-line flow meters…