Wednesday, March 15, 2017

Squirles Tank Renovation

They're hunting us.

Many nights before falling asleep I would stare over at my turtle's enclosure and long for something better. Hours of thought were spent trying to come up with a more suitable design. Something automated, cleaner and easier to maintain. This is my 4th, and perhaps not the final, attempt at creating just that.

Up to date photo for your convenience

In the summer of 2012, I was driving with my dad down the road from the house where my grandparents had lived in southern Indiana. On the road in front of us, I saw a turtle in front of our truck. I yelled for him to stop before he ran it over. Luckily he stopped in time and the turtle was fine. After getting out and grabbing the turtle, I took it back to the truck to show him. He knew right away that this was a terrapin. All I knew was that it was indeed a turtle. He asked if I was going to keep it, and honestly, the thought hadn't even occurred to me. I thought for a second and decided yeah, why not. That moment after I decided to keep the turtle, it peed on me. So naturally I named my new turtle Squirtle, after the Pokemon. I set her into an old Jimmy Johns 6 gallon pickle bucket, and we went on our way.

Later I learned that Squirtle is a female common box turtle of the species Terrapene Carolina. Knowing what I know now, I should have helped that turtle across the road and went about my life. The Terrapene c. carolina is a protected subspecies of the common box turtle classified as a vulnerable species. Their numbers are dwindling in part from urban development and the international pet trade. The common box turtle is listed on the Convention on International Trade in Endangered Species (CITES). Removing this species from its natural habitat is now prohibited in many states. By the time I learned this, it was too late. I had her in captivity long enough that reintroducing her to the wild would likely be detrimental to her and the other creatures. So I had two options: take her to a wildlife center that would possibly care for her or do my best to take care of her myself. I have been choosing the latter ever since.

I learned quickly that these turtles are quite the escape artists. I had removed her from the bucket and temporarily placed her outside, into a whiskey barrel that had long been used as a planter. The soil in the planter had to have been at least a foot and a half deep into the barrel. I thought surely she wouldn't get out. After coming back outside around an hour later, I discovered she escaped from the barrel. I was so hard pressed to believe she could climb out that I asked around to see if my relatives took her out. I figured if she did get out, she probably crawled over to the trees and foliage alongside the sound barrier for the interstate. I found her after about 3 minutes. Afterward, I placed her back into the barrel and sat back and watched her escape. I was amazed to see her find her footing and pull herself up and out of the barrel. After landing on the back of her shell, she looked hopeless and in need of assistance. But no, she used her head and rolled herself back and forth before finally righting herself up and continuing on back to the foliage.

Thinking back, one of my first assumptions on the turtle's whereabouts should have been birds of prey. Owls and hawks will often swoop down and grab them if presented with the opportunity. These turtles don't have the best eyesight and are as slow as a turtle, so they aren't well suited for escape. So this species is one of the few that evolved to be able to pull themselves into their shell and close the lid completely. A bird or animal is going to have a hard time trying to pry these things apart. Unfortunately for our turtle friends, they still have one weakness: gravity. Large birds have learned of this weakness and exploited it by carrying the closed turtle high into the air and dropping it over the hard, dense rock.

The only picture I have of the plywood habitat
Squirtle was back in the pickle bucket for the ride home to Illinois. When we got back, I built a small habitat out of plywood and plexiglass. She had one of those half log hideaways for a home, coconut choir for substrate, a small feeding dish and a very small pond dish for drinking. I was able to lift the plexiglass window in the front up and out when I needed access to the tank for cleaning and feeding. This seamed fine for the first few days but very soon I learned it just wasn't good enough. She didn't have adequate light, there were no plants, and the red worms that would escape her dinner were drying up soon after that. In fact, everything was too dry. And I learned something else pretty quick about these turtles too; they prefer to defecate in the water. So her drinking dish became her poop dish overnight. It was time to get something new.

I found some communities online for terrariums, vivariums, and paludariums and started on my own. I picked up an Exo-Terra 36x18x18 tank with the capacity for about 11 gallons of water at the base, and 2 hinged glass doors on the front. I made a land mass out of rock and soil on the left side of the tank and a slope into a filtered pond on the right. I planted moss and ground cover into the soil, placed leaf litter around her hideaway and had a new light fixture on the top with bulbs that would mimic night and day. In the water I had some blue LED lighting that looked pretty neat from the outside. The worms that would escape her dinner thrived just under the soil and procreated, giving the turtle a chance to hunt for protein at her heart's content. She enjoyed the water much better than the poop bowl she had before. And now that she had a light, she would climb on the top of her hideaway and bask for hours.

Lush Paradise
I was proud of this setup now. After all, it was a lot better than the dry plywood enclosure of before. Unfortunately, it soon changed from being a lush green paradise to a desolate, dirty wasteland. The dirt would easily erode into the water, and the filter was constantly clogged with mud. The land mass, because it was being supported by a mound of rock pebbles, was displacing so much water that I probably only had about 3 gallons in the tank. The soil was so saturated with water that plants were not able to survive for very long. When she would soak, she would involuntarily kick up dirt and debris causing the water to look like a murky mess.

Murky Wasteland
I knew I needed a way to separate the water and land. I needed to create a raised platform for the soil to sit in so that it could behave like a flower pot instead of a swamp. This would give plants the chance to thrive, as well as help maintain a cleaner pond environment for the added volume of water. I wasn't sure what material I was going to use for the platform. I was originally thinking I would sculpt a mold and vacuum form a strong plastic insert I could place inside and cover with dirt and rock. I was not convinced it would be strong enough and didn't want to invest in building a vacuum former to find out. After long consideration, I settled on cement. I would make the inverse of what I wanted and cast the insert out of cement.

Creating the mold for the cast was a very tricky thing to think about. I basically had to attach material everywhere I didn't want cement and leave negative space everywhere I did want it. On top of that I had to be able to pour my cement mixture into everywhere I needed it. So the mold had to be assembled in multiple pieces during the pouring process.
Makeshift hot knife using nichrome wire

Foam supports for the top piece
Anywhere I wanted empty space needed to have foam
I started the mold by measuring the inner dimensions of my tank and making a mock up version of the tank out of plywood, leaving 10.5 inches for the entrance to the water feature. I designed a very basic 2-dimensional version of what I wanted using CAD and printed out templates for cutting the foam. The foam cutting proved to be very slow using my hobby knife, so I made an electric foam cutter using nichrome wire and an ATX power supply. It worked pretty well, though I had to limit the current due to the foam melting so fast. The hot wire melted the foam right along the lines I drew and, after a light sanding, left nice smooth arches. I set those arches into the box and made precise measurements for the foam that would go in between. Since I wanted water to be where the foam inserts were, I had to prevent cement from getting through the cracks. Anything that wasn't a good tight fit needed to be sealed with hot glue before pouring the cement. I cut small support blocks to hold up the center piece of foam between the arches. The cement mixture was sure to be quite heavy, and I wanted to be certain the foam wouldn't bow or break where the ceiling was going to be. Most of the foam pieces were hot glued together. Unfortunately, I had to use my older glue gun because my new Dewalt one made the glue so hot it melted right through the foam.

Chicken wire to help support the floor/ceiling

I wasn't sure how necessary it would be, but I used chicken wire to help support the cement surface that would bear the weight of the dirt and rock on top, kind of like rebar. The following foam pieces were glued to where the cement platform would be in order to create access points for various additions or maintenance: four 3" x 4" holes at the corners and one 5" x 5"  hole in the center. The center hole will chute up and beyond the dirt level for easy access at anytime to the water below. Later, it will be covered with rock. 
Only 1 chance to get it right or I have to make it all over

Because the cement structure had walls and a floor, but I only had 1 pour to create the structure, I had to make an additional part of the mold that would hold the liquid cement down, which would allow the walls to rise to the top. Before pouring, I laid everything out in the order it needed to go back into the frame while pouring.

I didn't get a chance to make a video or take any pictures during the actual pour and mixing. The cement formula I used was 1 part water : 2 parts cement : 4 parts play sand. I actually ran out and had to mix more about halfway through. I tried to get the consistency the same but, as you will see further down, the difference is visible.

I let the cement sit for nearly 30 hours before giving in and ripping the wooden walls down. I was nervous about using a hammer to bang the walls off each other. They were glued together pretty tight; I hadn't used any nails. I decided to start off using clamps, and I slowly increased pressure until one side just popped off. Some of the boards broke multiple places, and I did end up using a hammer after gaining confidence the shock wave wouldn't damage the cast. What was left after removing the walls was to tediously remove the foam that remained in the structure. This is why I knew I only had one shot at this. The mold wasn't going to easily slide off the casting. I chiseled, stabbed and hammered the foam into bits to get it out. By the time I was done, I think maybe only one piece was left intact. After getting all the foam out, I was left with a heavy rough casting with uneven surfaces and flashing near where all the joints were. I filed down the rough spots and defined the arches in more detail until I was left with something close to what I had originally imagined.

Access holes in the ceiling for future peripherals. 

The white/grey concrete look was rather boring. I carved two sides to make it look like stacked rock or maybe something ancient that had long been forgotten. I started carving it by hand using a pick and file, but quickly resorted to a rotary tool and engraving bit. It took several bits and hours to carve two sides and the insides of the arches. I decided not to do the back and left side considering it would never be seen. My hand hurt pretty bad by the time I was finished. In the picture on the top left, you can see I cracked one of the legs. In actuality, I cracked 3 legs. I should have used supports for more than just the floor/ceiling. Luckily I was able to disguise the crack somewhat as part of the rock face later on.

Painted using acrylic paints and a brush
After finishing up on the carving, I black-washed the sides and top in acrylic black paint mixed with water. This was to get black into all the small cracks and "grout" lines in the carving. I used a dry brush technique and painted on tan, brown, green and red for the detail/accents. I think I found this part to be the most fun. You could really see it coming to life after each detail was added. I tried not to make anything too uniform to avoid it looking too purposeful.

Moved a wall to give turtle more clearance
I ran into an issue I should have thought through from the beginning. The entrance at the back right of the structure would become too narrow once I added in the foam backboard. My solution was to cut out the back wall and reattach it near the front (see bottom right picture for reference). This would give her an extra inch of clearance to fit through. To reattach the wall, I framed up the sides with foam, poured in some plaster/sand mixture and dropped in the top wall fragment. There was some runoff of plaster, and I had to touch up some paint afterword. Once I was satisfied with my edits, I turned the ancient structure onto its side, painted the rest black, sealed the bottom, flipped it back over and sealed the rest. It really didn't look too bad. The only issue was a small visible crack near the center, but other than that, it was great.

Had to shave material off threshold to fit structure in place
While the sealer was drying, I emptied out the tank and temporarily placed Squirtle into a 10 gallon plastic bin. She didn't like it one bit. The measurements I took at the beginning of this project didn't account for the bezel on the top or the door threshold on the bottom of the glass tank. Oops. In order to fit the Ancient Castle Rock Concrete Thing I had just built into the tank, I had to remove the top bezel and also remove a 1/4" of material off the threshold. The latch for the doors needed to be slightly modified as well to work properly. After that, I only had 1/8" of clearance for the structure to slide in. It took two people to lower it into place. The tank is sitting on a cabinet grade piece of 3/4" plywood I cut for the tank to sit on and to make it easier to transport.

I decided to throw away the old foam backboard that was in her tank. It was slightly discolored, broken, and I wanted something on all three sides, not just the back. I also needed to build steps leading to the top ground area. I made all these items from foam. I've come to really love pink insulation foam as a material. It is easy to cut and carve, and texture can be added quickly using any of the various techniques I've learned so far using this stuff.

I cut foam to fit in place on the sides and back of the tank and made sure to leave space in the corners and top for any tubing or wire that needed to be hidden. The steps serve a dual purpose: one being a filter and housing for the waterfall pump, and the other being, well, just steps.

After cutting each step to size, I numbered them and sanded them smooth. I wanted to make sure they were glued together in the right order with the correct side facing up. I know, it should have been easy to figure out just based on the shape, but I didn't want to make any mistakes. The rectangular holes near the back are for the filter and pump.

I made a lid that is held on with magnets and a block to prevent horizontal shifting when the turtle walks on it. I had to remove material from the bottom of the lid to allow it to fit nicely over the filter. I drilled holes into the side with the filter for the water intake.

I wanted to go for a natural layered rock look for the walls. I didn't really get exactly what I was going for, but in the end, I think it worked out.
Each of these "rocks" had to be cut out with the hot knife and shaped by hand with 60 grit sandpaper. It took longer to finish the walls than the concrete structure. I think each rock took about 3 minutes, not including texturing and painting.

I designed the walls and steps to be removable for cleaning and maintenance. The pieces are keyed to each other and lock each other in place. They also hold the steps down and prevent them from floating to the top.
Tank with walls removed
To the right is an image of the tank with the walls removed so I can show how it all fits back in. You can kind of see in this picture that the floor beneath the glass is not the same color as the plywood, like it was in the old tank. I painted and textured a sheet of foam and placed it in the gap under the glass. Even though I will eventually have some form of substrate on the bottom I wanted to make sure the wood bottom wasn't visible.

Steps go first
It was very important to me to be able to remove as much as I possibly could in case I ever need to make a change or swap out a component.

Wall piece keyed to the shape of the steps
The right wall piece needed to be split horizontally into two separate pieces. I did this because both pieces are locked vertically. The first piece of the wall to be removed needs to be pulled up from the side. The back wall has to be pulled up from the top, and the right side of the wall won't fit through the door. So I split the right wall in two pieces so that the top half can be pulled through the door.
The back slides behind the steps
The back piece has a conduit cut into the foam on the back side for tubes and cables to run hidden from view.
The top right side locks over the bottom
The missing rock in the top right corner is for the waterfall and fogger to slide into place locking everything together.
The left side and waterfall slide into place last

Once everything is together, there are very few things that indicated that the walls are even separate pieces. A little light comes in from some of the corner,s but I can mask that off later with something on the outside of the glass.

Testing the fogger and waterfall
The fogger/waterfall turned out pretty nice. It has a port in the back for the 1/4" tubing and another port for the fogger power cable. The top rock is held on with magnets and also friction from the walls. The fogger is nested down inside the other two pieces of foam. The way the fogger works is by vibrating a ceramic disk to create ultrasonic waves. The fog doesn't start getting produced until about 3 centimeters above the disk so I had to cut a hole in the top piece.

I gave the foam extra texture with a nylon wire brush and pressed a lava rock into the foam.
Like the cement structure, I painted everything black and then used acrylic tans, browns, greens and reds to detail and accent the rock.

On several places before black-washing, I brushed on some Plaster of Paris to fill in some grooves and give the foam a less flat surface. It also added a bit of heft to each piece.

Timer for day/night cycle
 At some point I added a panel mount timer to my light fixture. I grew tired of switching the lights from day to night and back to day. What I like about this timer is that it has a normally open contact and a normally closed contact. With this, I was able to switch between day and night with a single timer. But ever since I installed the timer, it just dangled on the outside of the tank. I wanted to mount it to the plastic light fixture for a while now, so I finally did. I measured out a square just big enough to fit it and cut the square piece out with my dremel. Originally I was going to remove both switches and replace them with the timer, but I decided to leave one switch in case I ever want to use it in the future.

The hideaway fit right over the walls by chance
The wood hideaway fit right over the two walls just by happenstance. I needed a place for her to hide and be comfortable but wasn't really sure what I was going to do, so I was happy that this just fell into place. I made steps from real stone cascading from the front to the back wall and cut a notch out of the log as a doorway for her to get to and from the pond.

Squirtle exploring her new digs

After everything was dry and the tank was cleaned up, I brought everything into the house from the garage where I was working and set it back up. The cement structure stayed in the tank and everything was very heavy. Once getting it all back together, I covered the maintenance holes with foam covers and filled the top to the brim with soil. I planted some foliage in the corners and scattered some small rock for decoration. On top of the soil I placed leaf litter and very small twigs, and on top of that, I let free around 48 red worms. And on top of all that, I laid down some damp sheet moss. I also covered the stone steps with sheet moss to make a more comfortable bedding in her hideaway. The red worms are meant to break down some of the leftover food and dead plant matter. She eats a lot of tomato and the seeds go everywhere, so little tomato plants pop up all over. They get trampled and die, and it's nice to know that any dead plants and leaf litter will get consumed. Interesting little fact: The worms don't directly eat the plants in a compost bin, but instead consume the micro-organisms that feed on the dead plants. The turtle will also regularly hunt for worms to eat as well and she is quite good a it.
Look of approval

Worms aren't the only protein she has to chose from either. In the lower portion of the tank live Rosy Red Minnows native to her wild habitat. If she pleases, she can go fishing and catch a snack. I haven't decided whether or not I want to let any crickets have a permanent residence in the tank. I like to research the various things I allow to live in her tank. I find out what they eat, what their bioload will be, and see what effects they might have on other species in the tank. A stable ecosystem can easily be desolated if the wrong species is introduced.
Clever girl.

Did I mention she is an escape artist? Some people questioned my steps, thinking they were too steep for the turtle to climb. The first thing she did after I placed her inside was check the walls and corners for weakness, like raptors at an electric fence. Turtlesaurus. Terrapinasaurus. Jurassic Turtle. I could go on.  I should make her a travel habitat that looks like the velociraptor enclosure.

Hard to get a good picture with the lights on.
The automation is currently run using 4 timers, but I will eventually use a PLC with the built in real time clock. Currently the only logic being used is timing. At 6am, the fogger turns on raising the humidity and spreading a cool haze over the land and water. At 7am, the fogger turns off and the aquarium light turns on as well as the top light switching from the night light to the daytime light. At noon, the bright warm heat lamp turns on to mimic the sun. At 4pm, the heat lamp turns off. Then at 10pm, the pond lights turn off and the top lights switch from daytime back to night. At midnight, the fogger turns on again. Once I have my PLC programmed and my sensors all added in, I want to install a misting system like you might find spraying the veggies at a grocery store and have it automatically water the plants. An auxiliary 10 gallon tank will eventually be housed in the cabinet underneath this one and will house a larger filter and pump. This will help keep the water balanced as well as auto fill the pond when the sensor detects that it is low.    

[Not finished, More to come]

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