We reached an important milestone in the project this afternoon. The power trio of Nathaniel, Rebekah, and Nathan – the core of FLC’s Data Science Club – got the Raspberry Pi installed and working to drive the integrated monitor, displaying a rolling presentation about the science – chiefly the nitrogen cycle – that makes the aquaponics system work.


As with most prototypes, the presentation needs a few tweaks, but it’s great to see all of the system components coming together.

Tweaking the Monitor Rotation

Nathan is working on the Arduino sensor array, and we’re still waiting to swap the science fish with the aquaponics fish, the latter in the quarantine holding tank in the Innovation Center.  The plan is to swap the green arcade button with a blue one, to match the colors in the presentation, and the button subsystem needs some attention, but overall the project is finally starting to feel like it might one day be finished!

Nathaniel, Rebekah and Nathan Contemplating Raspbian

With the fall show winding down, Cameron and the Theater Arts crew are trying to get the aquaponics system wrapped up, and brought the near-finished display up to the library for a dry-fitting.


I’m told they’ll have it buttoned up within a week, after which all the other work – getting the tank established, setting up and calibrating all the sensors, connecting all that to the network, figuring out the display and the giant “get tank vitals” arcade button – can continue in earnest.

We’re also close to getting the nine tiles for the first pane of the Carvey project finished, inspired by Jeff Solin’s Mosaic Tile project. Nathaniel and Rebekah of FLC’s Data Science Club carved up a version of their club logo to add to the other faculty and student tiles we’ve got so far.

Removing the carved tile.

The plan then is to mill (on the big ShopBot down in Theater Arts) a 3×3 tile “waffle” frame, with recessed wells for each of nine tiles. That will comprise the first of hopefully many such 9-tile collections, as additional faculty, staff and students create their own tiles, and all that work will be on display, either outside or inside of the Innovation Center.

Carvey Totoro


Carving Done


Max Mahoney (Chemistry) and I met today to do some preliminary sensor calibration for the aquaponics system.  Max brought over various solutions of known pH and µS/cm.

Solutions of known pH for aquaponics sensor calibration

We connected the pH sensor to the Cooking Hacks Open Aquarium shield, and went through the procedure of calibrating the sensor, which involved basically sticking the sensor into a beaker of various solutions, recording the values, and tweaking some variables in the Arduino sketch.

pH calibration for aquaponics sensor

The process for the electroconductivity sensor was much the same. Both worked without a hitch, and once the calibration procedure was complete, we tested the water from the experimental system – 7.54 ph/298.24 µS/cm – and from the quarantine tank – 7.07 pH/176.83 µS/cm. There’s something up with the temperature sensor, which gives a zero value no matter what, so we’ll need to get that sorted, but overall a very successful work day. To top it of, the power and Ethernet should be installed out in the library tomorrow!

Max calibrating pH sensor for the aquaponics build

Still waiting for the power and some other critical infrastructure pieces for the library aquaponics system to line up, so I’ve been working here and there on an open source, 3D printed drip system that uses recycled soda bottles as plant containers.

I was never quite able to get the venturi – the piece that uses air from an aquarium air pump to push water up a tube to water the plants – to work properly. It would work for a few hours, and then quit, I think because of clogs in the tiny air courses, so I set out to explore other solutions. Working off of an idea I found on Instructables for a bubble lift hydroponics setup, I headed to the hardware store for a few items, and was able to cobble something together.  Science!

Aquaponics Drip System - DIY Venturi

It’s been running all day, and seems stable. I’ll let it run overnight just to be sure, but I felt confident enough to stick some mint cuttings into the bottles, and hope they’ll root.

Aquaponics Drip System, Dripping

While waiting for the various parts and processes to resolve for the aquaponics project, I’ve been experimenting with 3Dponics, and open source system/community for 3D printed aquaponics parts.  To set the system up, I cut and punched holes in plastic water bottles, then printed screw-on drip nozzles (CC BY-SA, 3Dponics), and an aquarium air pump driven venturi to provide water for the system.  With the venturi in the experimental system/quarantine tank, I turned on the pump, and the whole thing seems to work perfectly!


I’m going to let it run for a few days to make sure things are good to go, and then I’ll fill the bottles with plants.  My current thinking is to root mint cuttings.  Mint is perfectly happy in wet and low-light situations, and roots readily from cuttings.

The project is slowly coming together. Yesterday, the ECO-Cycle Aquaponics Kit arrived!

Aquaponics Infrastructure

We’re taking some shortcuts with phase 1 of this project, combining kits where available, in an effort to shorten some of the development time and get to a public roll-out sooner.  Now that we have the actual setup, we can proceed with the final design phases of the tank base, which will include some variation on the nitrogen cycle diagram.  Max Mahoney (Chemistry) has the pH test solutions ready, so hopefully next week we can get the sensor array working.  In other news, I heard from IT, and they’re coordinating with the electricians to complete the network drop when the Library floor is opened up for the electrical work.  Slowly but surely…

Made some spectacular progress on the aquaponics project, producing a prototype of what will eventually be the light-up infographic built into the base. The team collaborated on a design for a diagram of the nitrogen cycle, and with the help of Ian Wallace (Professor, Theater Arts) and Cameron Hoyt (student and designer of the tank stand), we were able to get the design cut out on the big ShopBot in the scene shop.

Tools have their own logic, and CNC is no different. Balancing legibility of the design with the properties of the materials and the constraints of router bit size was a learning experience. The initial design was text heavy, but the 1/8″ bit introduces some size constraints. That is, the text has to be large enough for the machine to cut. After consulting with Ian, I scaled up many of the lines, adjusted the font, and created a little 1/8″ dot to drag around the image as a simulated router bit.  The original is on the left, with the revised version on the right (below).

Aquaponics Project: Nitrogen Diagram Before and After

Ian took the draft diagram and ran it through software to create the tool path. Some scale work still to be done, especially on the text, but we decided to run a test cut anyhow.

Aquaponics Project: Ian Checking the Nitrogen Cycle Diagram

I watched and learned as Cameron and Ian set up the ShopBot and got things ready to carve…

Aquaponics Project: Ian and Cameron Helping to Set up the CNC Job

…after which I babysat the machine, which took about 30 minutes to cut out the prototype.

Aquaponics Project: Nitrogen Cycle CNC

Below is the prototype, after a little cleanup with a knife, sandpaper and a file.

Aquapics Project: Nitrogen Cycle CNC Prototype

There’s still some design work to be done, and some tightening and scaling to make the diagram legible, but we were very pleased with this rough version. Always be prototyping!

The gear is beginning to roll in! As with any reasonably complex endeavor at any reasonably complex institution, procuring the “stuff” to make a project work takes a great deal of time and energy – lots of rules and forms and budget strings and signatures and hoops to be jumped through. For this particular project, the electronics – chiefly Arduino shields and associated sensors – are sourced from a Spanish company called Cooking Hacks.  We chose this particular system because a) the parts seem to be well integrated and seemingly well thought out, and b) Cooking Hacks seems to have the code worked out, not just for the shields and sensor interfaces, but for the server-side bits that make the web integration work.  In short, the goal is to get a prototype up and working with a minimum of coding and fuss, and the Cooking Hacks gear seems to fit the bill.

Making Across the Curriculum - Aquaponics Project Hardware

I was able to get most of the sensors working in relatively short order, so I’m feeling good about the progress.  Still waiting on the purchase order for the tank itself, and the ECO-Cycle Aquaponics Kit for the top, but we were able to get a small test tank up and running, thanks to some spare parts the Biology Department was able to scrounge, and some help from Max Mahoney (Chemistry).

Making Across the Curriculum - Aquaponics Project Test Tank

In addition to the little aquaponics setup above, we gathered up another unused 23-gallon tank, complete with filtration and gravel and all the parts necessary to bring up a complete “development instance” of the project in the Innovation Center, which we’ll use to test the electronics, and to get the water and filtration and fish and procedures sorted out.  Progress!

Met with Cameron Hoyt (FLC Theater Arts student and primary design and construction resource for the project) to go over some initial design drawings.  We talked through a bunch of considerations regarding size, scale, construction, safety, design, integration with the space, ease of access, cable routing, and other things.  I’ll be seeking input from the other project primaries – Biology, Chemistry, and Library faculty – as we further refine the project and enter the build phase.

Making Across the Curriculum - Aquaponics Design Drawing 01

Making Across the Curriculum - Aquaponics Design Drawing 02

Full set of drawings