Planted Tank VIP
Join Date: Jul 2002
Location: Victoria,British Columbia, Canada
Before you build
Before you even begin to plan your terrarium design you need to consider what you want to house in it. This decision will drastically impact your design choices and you selection of plants. For the sake of this article, I am planning a terrarium around Poison Dart Frogs and have to choose my décor, plants, and water depth appropriately.
My decision to house poison dart frogs limits my plant choices to softer leaved varieties such as Mosses, baby’s Tears, creeping fig, ferns, and various others. Dart frogs have very tender skin and they can be injured by pointier plants. In addition to my plant limitations, I will have to be very careful about how I place my water features. Dart frogs are notoriously bad swimmers, and without proper care they could drown in an otherwise shallow pool.
Always, ALWAYS, plan before you build. A little time spent up front can save you hundreds of dollars and a lot of heartache.
There are many options available for substrates in a terrarium, and each one should be considered carefully, if you have already decided what you are planning house in your terrarium this should make your decision easier.
For the purpose of my Dart Frog Terrarium I have selected a layered substrate. The bottom of the terrarium is lined with a large grade pea gravel (normally used for yard landscaping, smooth pebbles around .5”). This layer is approximately 2.5” and is used to raise the planting layer out of the water line.
A section of nylon mesh window screen is used to separate the layers of substrate from each other. You want to avoid having your drainage layer (the pebbles) from becoming obstructed with the finer materials. You will not be able to see this screen if it is cut to fit.
On top of the window screen a thicker layer (2-3 inches) of coconut fiber or potting soil is placed (potting soil has a tendency to get moldy and will need to be replaced more frequently). I prefer to use Coconut fiber despite its slightly higher cost for a variety of reasons;
1.) It holds moisture better then soils, without getting sopping wet
2.) It does not mold very quickly
3.) It is very light
Unlike an aquarium the plants normally used in a rainforest terrarium do not require very much light at all. These plants have adapted to life under the forest canopy and very rarely would see direct sunlight. In fact, my 60 gallon tank will only have 2-3 40 watt bulbs. Full spectrum lights are very appropriate for this setup, and I find that my older aquarium lights are excellent for the terrarium.
This is probably my favorite part of the terrarium. There are a number of species that are well suited to the terrarium as long as you can meet their requirements. For the rainforest terrarium you will want to select plants that can tolerate a higher humidity, as this will be a very damp enclosure. Mosses and Lichens are excellent for this setup, and many can even be harvested locally (especially if you live in the Pacific Northwest). Many air plants and Bromeliads are also good choices as they can tolerate many different conditions (some dart frogs even require large Bromeliads to breed in!).
I have selected a variety of tropical plants for my terrarium and will be experimenting with them over the next several weeks;
1.) Creeping Fig (several species)
2.) Baby’s Tears
3.) Irish Moss
4.) Local Mosses
5.) Pothos (always a good choice)
6.) Varying Ferns
This is a subject to be considered seriously. If you are planning on housing animals that require a relatively stable level of humidity, or your intention is to breed them, you may want to consider building or buying a humidifier. I am currently building a system that will operate on a timer to mist the terrarium several times a day so the frogs will be happy.
Your choice of substrate should be heavily influenced by what your humidity requirements will be, as some materials will not hold the moisture very well and can cause the terrarium to dry out. Dried mosses, coconut fiber, peat, etc can all be used to hold moisture in a terrarium, but they all have different maintenance requirements.
If you do not wish to purchase an automated system, you will have to make a regular routine of misting your terrarium as per your animal’s requirements. This may be once a day or even as high as 6 times a day depending on your surrounding environment. Plan carefully.
You may wish to add a water feature or two into your terrarium. This can become a wonderful focal point, and actually perform a valuable service to your micro eco system. You will want to plan you water features carefully, as certain animals may not be able to rescue themselves if they happen to stumble into a body of water. I have decided to create a small waterfall that will cascade out of some slate pieces that are siliconed together, and down a slate channel that is lined with large pea gravel and aquarium gravel. Creating a stream in this manner means that there will not be any real deep area’s and water will simply flow around the pebbles. If the frogs stumble into the feature they can simply crawl or hop out.
In addition to visual appearance the water feature will provide a few valuable services. First of all, the running turbulent water will help keep the relative humidity up. Secondly, the water flowing through a gravel bed will actually provide some minor biological filtration, as bacteria will break down waste in the same manner it does in an aquarium. This process is actually more efficient in a stream situation as the bacteria has more contact with oxygen in the air, acting like a wet dry filter.
You will need to power these features using a small pump, power head, or internal aquarium filter. I will be using a small aquarium filter that I can stock with Carbon to keep odors down.
You can use many different materials for your backgrounds, they each have their own benefits and drawbacks. Typically speaking you will want to select something that suits the needs of the terrarium (IE: Does it hold moisture to keep humidity up? Is it a good planting medium?).
For my terrarium I have selected Cork bark and Slate pieces to create a natural looking environment, and provide a stable, lightweight background to plant air plants into. The only downside to this design is that cork does not hold moisture very well so I am compensating by using an automated misting system.