Anyone who has operated their own aquaponic garden knows that you can grow food with fish waste, but can you grow food with other aquatic creatures? Can you grow food with turtle waste? Is it safe to eat? Those were the questions I set out to answer with this fun project/experiment I call, Turtleponics.
I acquired some turtles for free via Craigslist, Shelly, a Midland or Eastern painted, and Scooter, a Northern map turtle. They came in a 30 gallon tank, which was much too small for two turtles of their size.
I made due with the tank as long as I could, but I knew they needed a bigger home.
I had an extra 55 gallon tank a had recently restored. While the 55 gallon wasn't that much of an increase in size, I knew I wanted to build some sort of addition on top of the aquarium to maximize tank space. A little Googling revealed the magic words, Above Tank Basking Area, or ATBA. Once I had that keyword, finding what I wanted was a breeze. There are many great builds out there, but this YouTube video from Liam ended up being my biggest inspiration.
There are dozens of YouTube videos that guide you through building an aquarium stand. I found this one for building a 55 gallon tank stand particularly helpful. That said, I probably watched every video linked on the side, ad infinitum.
The first step was to design the tank in modeling software before buying supplies. Using SketchUp, I created a model of what I hoped to build.
I had done all the modeling and YouTube research I could muster. It was time to start building! Using the wood shop at my local hackerspace, Solid State Depot, I started by making two matching frames.
The dimensions for the stand were slightly larger than the 4' x 1' tank and 32" high, tall enough to store a couple 5 gallon buckets and supplies, once completed. Here is the cut-list I used, if you'd like to follow along.
A plywood base was added to the stand before the top frame was secured.
Leftover plywood was used to make a shelf on the right side of the stand.
Next, 1/4" plywood panels are cut and tacked to the stand frame.
The sides, front, and top are all covered and ready for trim.
Simultaneously, the ATBA is built out of 1"x12" and 1"x2" pine boards.
Getting the basking area to fit is crucial, so many test fits are performed.
I made the top of my ATBA a little more robust than I saw in other videos. Most builds used egg crate light difraction as the top. I opted for wire mesh instead and used a staple gun to attach it to the underside of the top ATBA frame. I also attached a top-bar to allow the hanging of basking lamps and UV bulbs, as well as lighting for the aquaponic system.
Using some 1" x 4" pine boards, trim was added to the top and bottom of the stand. Corner molding was added to the edges to hide the plywood panel seams. I also added some trim around the front and sides of the ATBA so it would not slide around on top of the tank.
To allow visibility of the turtles while in the basking area, two pieces of plexiglass were cut at the hardware store to act as sliding glass doors. Similar to other builds, I bought some sliding door tracks online, and adhered them to the upper and lower bar of what would be the sliding doors.
For the inside of the tank, I wanted to create an undergravel filter. The turtles can be pretty messy, so having as much filtration as possible is necessary. I planned to attach a powerhead to the filter, which would then feed up into the aquaponics grow bed. I had built a similar setup for a previous aquarium, so I took that model and scaled it up. I used 1/2" PVC and cut each piece to fit in either a t-joint or an elbow joint. Then, each section was taken to the drill press and drilled. I also created some turtle hides from terra cotta pots. This video was a huge help for that. It still took almost a whole package of cutting disks for the Dremel to make two caves.
The last major hurdle in building the stand was making cabinet doors. I had never made doors and had to consult with the resident wood guru at the hackerspace. I opted to go with some flat panel doors. Again, internet videos played a big role in helping on this one. I picked up some really nice adjustable hinges and attached them using a Forstner bit.
The moment of truth came when it was time to hang the doors. Despite giving myself an extra 1/2" on each side of the door, I still managed to make them smaller than was intended. However, they fit over the cabinets well enough, and the adjustable hinges made installation a breeze.
All the hardware is mounted inside and out to ensure proper placement after finishing the wood.
I couldn't decide if I wanted to stain or paint then stand. I decided stain could always be painted over, so I stained it first to how how it would look. It was terrible. Using so many different kinds of woods made for a poor staining canvas. Luckily, a few coats of primer gave new life to the stand, and it was ready for a paint job.
Three coats of black latex paint and two coats of clear simi-gloss finish later, and the stand and ATBA are looking almost professional.
A pair of black door knobs added the finishing touches to the stand.
It was finally time to move the stand indoors. With the stand and the tank ready to go, setting up the ATBA was the last challenge.
A small tote found at the hardware store seemed like an ideal mini grow bed for the turtleponics system. Not only was it a great size, but the lid also made a great ramp for the turtles to access the food grow in it. Also worth noting, I used countertop laminate to cover the back wall of the ATBA. I had to buy laminate glue and a special roller to install it, but it looked really nice in the end.
For the lid/floor pieces, I went to CO Plastics and got some 1/4" clear acrylic sheets, which were laser cut to fit right on top of the tank. The back two conners on both pieces were cut out to allow filters and other tubes or cords to easily pass up and out of the tank. Clear acrylic was chosen so lights on the backside of the ATBA could illuminate the tank underneath. One half had holes cut to allow the aquaponic plumbing to pass through. The other side had a ramp cut out, with many holes cut in it to give the turtles something to grip when climbing up. I used two hot-air guns to heat both sides of the acrylic at once and then bent it to create the ramp into the ATBA.
In the other ATBA videos, most used fluorescent lights. For this tank, I wanted to use LED lighting as well as make it "smart" so it could be programmed to rise and set like the sun and follow seasonal patterns, shutting off earlier in the winter than in the summer. You can read more about the LED lighting over at SparkFun.com.
The LED lighting worked wonderfully and made the tank really stand out.
A canister filter was installed before I packed too many supplies underneath.
Using the leftover laminate from the ATBA, the lid/floor pieces were partially covered. The back portion of each was left uncovered to allow the light to shine through to the tank. The laminate not only looks nice but also makes cleaning up any messes in the ATBA super easy (I've yet to see either turtle make a mess out of the water though). I later attached some rocks with some silicone, to give the turtles more foot holds when climbing in and out of the water.
I painted the outside of the grow bed to prevent light from hitting it and causing algae growth. The plan was to make it a timer-based ebb and flow system, similar to my other aquaponic systems, running for 15 minutes every hour. The powerhead was connected to an inlet going into the bed, and a tiny downspout allows the overflow to flow right back into the tank.
With everything setup and both filters running, it was time for the great moving. I let the water in the tank cycle for a couple days before putting in the turltes. Shelly had no problems getting up to the basking area. She immediately took advantage of the new digs.
Now it was time to see if the turtleponic system would work and if the turltes would actually eat from it. I planted some lettuce, which sprouted in no time.
Shelly didn't care.
Once she got used to the ATBA, she stopped climbing all over the grow bed, which allowed the lettuce to grow in peace.
Originally, I made a perimeter out of rocks siliconed to the floor of the ATBA and added small gravel inside the perimeter to replicate a beach or shore. It worked ok, but the turtles ended up knocking all the rocks out. In their stead, I added some larger basking rocks, and just in time as molting season had begun.
A large plecostomus, named Oscar, was added to the tank to help minimize the turtle mess. I was worried the turtles would kill him, as they've eaten any small fish put in with them. Shelly took a few chunks out of his tail, but that was the extent of the damage. It grew back just fine.
It took more time, but Scooter finally started to get used to the new basking area, making the occasional appearance.
The lettuce really started to take off. But, did Shelly care?
No, she did not.
While the turtles have yet to eat any lettuce straight from the system (I've been informed that it may be impossible for them to eat food without the aid of water), the experiment was still a success in my mind. I can produce more than enough lettuce to feed to the turtles and Oscar. It provides added filtration on top of my canister filter and undergravel filter, and it adds a little natural decor.
On top of all that, I managed to accomplish what I set out to do and make a better home for these amazing creatures. They now have more room to swim, and they have plenty of room to bask to their heart's content. Though that doesn't stop them from doing a little stacking.
In the end, I all I wanted was happier turtles, and I think this image sums up how they feel.