The Eco-Crystal - Mini Ecosystem in a Crystal Shaped Planter

The so-called "bottle gardens" have always fascinated me. What could be more impressive for all garden lovers than a tiny ecosystem in a jar in your living room?

I have wanted to own such a mini biosphere for a long time. And because it makes more fun to build your own one instead of buying it, I tried to create my own one for a few bucks. I searched the web for inspiration, and found a few ecospheres, which looks pretty nice. I decided to take this ecospheres as a "template", and start to build my own. I made a few simplifications: I don't have a door with an invisible hinge. Also (the biggest difference!), my sphere is not made with glass! I used acrylic glass, just because it is simpler to work with for me.

I documented the building process, so you can build your own biosphere with the help of this instruction. You're welcome :)

How can this garden live?

This ecosystems can be created both in open glass containers or in closed ones. The closed one is called a hermetosphere and is a self-contained ecosystem in the form of a small, sealable glass container filled with plants.
The plants absorb water from the substrate and partially evaporate it through their leaves. This condenses on the inner walls and drips in the form of rain onto the substrate, where it is available to the plants again. They obtain nutrients from dead plant parts. The plants use photosynthesis to filter carbon dioxide from the air and release oxygen.
Your bottle garden is a small ecosystem consisting of earth, plants, microorganisms, air and water. In this small world, not a drop of water is lost - just as little as in the large role model - the cycle on our earth.
... Well, a little water will be lost over time because we can not perfectly seal the sphere :)

Why the Crystal-Shape?

Because I want it like that! :)
And, to be honest, it is easier for me to make shapes with flat surfaces instead of round ones.

There are not much supplies for this project, which makes the biosphere very cheap!

• Acrylic glass plate, 500x500 mm, 2 mm thicknes
• Strong glue for plastics (I used this one)
• Maybe for the door: Strong magnets (Neodym), small sized

That's it :)

For the socket with the lamp, I used the following materials:

• An old flashlight
• An aluminium tube, a bit longer than the sphere is high
• 3D printed arm
• Material for the socket as you want, I used wooden plates

The Tools I used were the following basics I already had at home:

• Masking tape
• Cutter knife
• Metal ruler
• Printer to print the paper stencils
• Soldering iron for the lamp
• Wood glue for the socket

If you have a 3D printer, this can be helpful, too! But this is not absolutely necessary. See the point "Glue the parts together" or the Addons.

Bevore we start with the building of the biosphere, I want to give you some very basic information regarding the substrates and the plants, which are suitable for such a project.

First, the substrate:

Not every substrate is suitable for planting a bottle garden. Unsuitable substrates such as conventional potting soil, would mold very quickly. The right substrate is the basis for a functioning mini biosphere.

• It should be stable, coarse-grained, durable and not compacted
• Inorganic materials with grain size from 2 to 6 mm are optimal
• Light and stable expanded clay is perfect for it
• Basalt split and lava granules, is great too, because of the open, porous structure
• Pumice and Akadama, a purely mineral granulate, is suitable

Lime-containing substrates such as marble gravel should also be avoided, as they could chemically alter the environment in the glass. What does not work at all is pre-fertilized, commercially available potting soil. It gradually becomes compacted, which impedes gas exchange and can lead to rotting. It also releases nutrients, which leads to undesirably lush plant growth.

Then, the plants:

For planting, depending on the shape and size of the glass, slow-growing plant species that remain small are suitable. They should be robust, tolerate constant moisture and low nutrients, do without direct sunlight and generally have similar requirements. Climatic conditions in their natural habitats should be as similar as possible to those in the glass. Exotic species such as mini orchids of different orchid genera and bromeliads are particularly suitable for a garden in a glass. Mosses such as sphagnum mosses, small-growing ferns, ornamental pepper, zebraweed, mini green lilies, the three-master flower (Tradescantia) and even carnivorous plants also do very well. In any case, they should be healthy and pest-free.

TIP: If you want to built an open instead of a closed bottle garden, drought-loving cacti and succulents are perfect! To be honest, they are suitable only for open bottle gardens.

First, print the stencils for your glass. If you want to build a sphere like mine, feel free to use the stencils (PDF files S1 to S4) I attached in this step. Then, cut the stencils out.

Then you can place the stencils on your acrylic glass plate and fix it with a few strips of tape.

Put them on a carped pad, place the metal ruler on the cutting edge and make the first cut with the cutter knife. Do not make the first cut too forcefully, but precisely. Then make 4 to 5 powerful cuts along the edge. That's enough. Do so with the other edges of the shape, too. When you done all sides, turn your glass and do the same from the other side. Try to hit the cuts of the other side as good as possible.

When you are done, you can carefully break out the glass plate.

Do this with all your plates. At the end you will have 11 Plates.

In this step, a 3D printer could be helpful, but it works without one, too.

After the plates are cut, they must be positioned and arranged as the crystal and fixed for gluing. You can arrange them and fix it with strips of the masking tape.
Or you can 3D-print little helpers :) I attached the stl-files for the positioning aids I used to this step. These are little angles with a gap of 2 mm, the thickness of the acrylic glass I used. Every part has its own position where it helps you to fix the glass plates. I attached a picture to which positions the aids belong to.
I printed them without supports, 0.2 mm layer. The flat side without the slot as the base. A1 and A2 must be printed 4 times.

With the positioning aids it is very simple to position your plates for a first gluing. Without, you have to be more patient and need more dexterity with the masking tape.

FIRST GLUING

In the first step, take the plates No. 5 (1x) and No. 6 (4x). These are glued to the lower part of the crystal. Fix them. I used the printed aid part A1 (4x) and for the bottom plate I took the tape. When it's fixed, start gluing.

I used a plastic spatula to apply and spread the gooey glue around the edges. With the specified glue it is not bad if it looks a little messy. When it is dry, any excess can simply be rubbed or cut away.
Glue the boards together by smearing the glue into the edges from the outside and also drawing a thick edge from the inside.

When the glue has dried, test this shell to see if it is tight. This is where the moisture will be collected later. If there is a leak here, it will drip out of your ecosphere. For the test, fill the bowl with water and wait. If after an hour no water has leaked out, perfect. If it does, you'll need to touch up.

SECOND GLUING

Then I took the plates No. 1 (2x), No. 2 (2x) and No. 4 (1x). I fixed them with the little helpers, and start adding the glue with my spatula. From outside and from inside.

ATTENTION: I assembled here both of the plates No. 2, but I only glued one of them. The other is later the door of the sphere and was only fixed to ensure the accuracy of fit of the other plates. Just glue one of them!

When you finished the first and the second gluing, let it dry.

THIRD GLUING

When the parts from the second step are dry, remove the helping parts and the door plate and fix the plate No. 3 (1x) to it. Same procedure, glue the edges from inside and outside.

Let it dry.

FOURTH GLUING

When it dried, it is time to assemble both big parts together. Fix it with tape and glue them together.

HINT: The bigger the inner joints are, the more stable is the sphere later on. But, well, the bigger the joints, the less beautiful it looks. Do as you think it is fine for you.

This is maybe the most difficult part of building the sphere. The door should be tight so that the moisture can not escape.

To create a kind of seal, I used the glue to apply a thin layer to the edges of the door frames. When the door is placed and is pressed against the panels, this makes the door tight. When applying this "seal" to the frame, you must be very careful to apply as smooth a layer of glue as possible.
But how is the door panel attached now? I have tried it with neodymium magnets. I glue one in each corner of the frame (a little inwards) and the counterpart with superglue to the door plate. That worked pretty well at first. But I guess my magnets were too strong or the glue was too weak. After opening the door a few times, I ripped the magnets out of the frame and it hung on the door. So here it is a bit of trial and error which magnets have the right strength to hold the door, but are not too strong that they are torn out of the glue.

My final solution:
I attached a strip of clear tape to the long edge of the door and used it to tape the door to the edge of the sphere. The strip of tape is almost invisible and works as a hinge. I glued two magnets to the opposite corners. I cut my strong magnets in half to reduce the force. So far, this solution works quite well :) Yippieh!

If you have any ideas for a better or different solution, feel free to post them in the comments. I am curious.

Finally, you are ready to bring the life in your biosphere!

As already written in the second step of this instruction, you need a right substate as a base, not conventional potting soil. See step 1.

The bottom layer is there to allow the water to drain down. I used expanded clay in the ground, two hands full of it. In this way, there is no waterlogging and the roots of your plants do not get too wet.

TIP: Place a piece of charcoal in the base! The charcoal has a disinfectant effect and serves to kill harmful microorganisms and bacteria.

On top of this granulate base, you can arrange your plants. Try to cover the whole area so that the water definitely rises through your plants.

I took a walk in a nearby forest that is a little swampy. I collected some different mosses which all grew on the same place, so they live in the same environment with the same humidity. Also I found an overgrown piece of wood. With this collected plants, I created my own little garden inside the biosphere. I cleaned the plants from Pine needles and other stuff, and arranged them the way I want. Here you can become creative :)

I realy like the result :)

It may take a few days for your garden to reach its balance. Watch it and open or water it as needed. Once your garden is in balance, it will not need watering for a long time.

Sufficient water in the Crystal:
There are always a few drops of water on the walls of the crystal.

Too much water:
If the inside of the sphere is misted up, you can open it for a few hours to allow excess water to evaporate.

Too little water:
If no drop can be seen inside the glass, open the glass and pour a little.

Your garden found its balance? Great, so now it's your turn to find it as well :) Enjoy your new little ecosystem at home.

There are a few possible addons I thought about, e.g.:

• A base frame to make it more stable
• A nice little lamp to light all up
• A small hygrometer

The last point, I haven't had built till now, fist I want to try it without, but I think when I am facing some problems with my garden, this would be helpfull. I'll explain it below.

BASE FRAME

To give the base a more stable frame (I am a little scaredy cat ^^ ), I 3D-printed a base for it. This could be glued to the glass shell and make it more stable on the ground.

I attached the STL file to this step, feel free to use.

LAMP WITH A SOCKET

I really recommend this step, it makes your work shine in a whole different light. For this step, I disassebled a old flashlight. We need the lense, the switch, the LED, the battery case and the reflector. In addition I used a aluminium tube, some wires, a 3D-printed arm and wood panels for the base.

3D-print the arm (STL file attached) and pull the wires (V+ and GND) throug. Then solder them to the LED. Then inserts the LED into the arm. On top of it the reflector and the lens of the flashlight. If you use a lamp like mine, you don't need glue for this step, the parts can just be pressed in.

Saw the aluminium tube to length: A little longer than the Ecosphere is height. Pull the wires throug the tube and assemle the arm to the tube (gently press it on).

For the base I drilled a hole for the tube and a hole for the on/off switch in a wood panel. The battery case I simply glued under this panel. I saw the side parts for the socket out of other panels and glued it together with wood glue.

The Tube and the on/off switch were glued on the panel as well. Easy.

HYGROMETER

This might be usefull, but as I wrote, I didn't use one till today.
If there are some problems with your gardened plants, it will be helpful to know the humidity inside your ecosphere. For this I could imagine to use a small hygrometer (like this), arduino based, with a small display. The microcontroller could be hidden in the socket. For the wires, I would cut a small slot in the glue, pull the wires through, place the hygrometer inside the sphere, and close the slot again with glue. The outgoing wires could be wired to an ATtiny85 or an arduino nano or something similar...

I think you know what I mean with this step ;) Would be helpful, or what do you think?

Do you have any other ideas on how to expand or improve the crystal? I am curious about it, because I would like to build a second one, maybe in a different shape. I would like to try out your ideas, so let me know.

I would be very happy to see pictures of many mini ecosystems in glass containers soon. Have fun mini gardening around and stay healthy!