Integrated System Build & Test
Table of Contents
Team Vision for Integrated System Build & Test PhaseSummarize: The goal of this phase was for our team was to completely build and assemble the aquaponics system including the plant bed, tanks, support structure, PVC piping, pump, and sensor system.
Build ProgressOur team was able to build our complete design assembling the aquaponics system. Our build consisted of assembling the plant bed, applying flex seal, and attaching PVC piping and pump. Pictures of our build are shown below:
The above images show the dimensioning and cutting of materials for the plant bed (left), assembly of the plywood support frame and legs (middle), and assembly of plywood on the structure.
The above images show the assembly of the plywood support frame and legs(left), the application of flex seal to the plant bed(middle), and the completed design of our aquaponics system.
Additional support will be added to the existing structure. Plywood boards will be added to run length of support legs and will connect each leg. This will provide an additional factor of safety against failure of the structure due to the movement of water in the plant bed. Metal brackets will also be added to the corners of the side walls. This will help to prevent leakage. These recommendations were mandated by Robert Kraynik (Facilities Manager) on 3/28/19 to be implemented before the system can be filled with water for safety reasons.
The above images show the updated CAD which includes the boards added to legs to prevent deflection.
The pump design was modified to constrain the plunger so it could not be pulled out on accident. The main shaft of the plunger decreased in diameter so the hole at the top of the vaccum chamber could also have a smaller diameter. A larger cap was put on the end of the plunger (with the o-ring seal) so it would not be able to pass through the hole at the top.
In the final assembly of the system, the pump was not resting flat on the ground because of the increased diameter of the filter beside it. A wooden base was added to make up the difference and it was built to also provide a place to put your foot when pumping for easy leverage.
Sensor SystemThis phase, we added a dissolved oxygen sensor to the sensor system. This involved not only adding the functionality to the code but also setting up the device properly. To do this, we acquired Sodium Hydroxide (NaOH) and filled the probe with this solution to allow it to properly detect the the concentration of the oxygen dissolved in the water. The following is a simple connection diagram for the current system.
For the powering of our system, we found that our previously acquired solar charge controller would not work for us since it required much more power than we are going to generate with our solar panels. We are currently in talks with a Field Sales Engineer from Analog Devices to acquire a lower powered solar charge controller. This controller will also dictate the type and size of the battery we will use.
Finally, we are working on moving the system from a breadboard onto a Arduino MEGA Shield to make the connections more permanent and secure. Before selecting an enclosure, we are waiting until we have chosen a solar charge controller and battery and we know the physical size of every component, so we can choose a project enclosure that is of an ideal size.
Test Results Summary
Our team also conducted several tests to ensure our system met all design requirements.
The first test consisted of checking the dried flex seal for holes where coverage was not ideal and adding water to check for leaks. In both cases, additional flex seal was applied to the ploblematic area of the plant bed.
The second test we conducted focused on the ease of use of the pump.
The same pump test we used to verify the original pump design was repeated with the modified pump design.
We timed 20 strokes (up and down) and measured the volume that was moved in that time. The results are shown below. Based on the new data our recommendation is still to pump the system 20 minutes in the morning and in the evening.
The filter design hasn't changed since last review. It has now been built in the piping system and will be tested in a full system test once the rest of the aquaponics system is built.
Plans for next phase
- We would like to have accumulated knowledge of aquaponics systems to hand off to our customer along with completed poster and paper.