I saw a similar looking project on the internet, and thought it would be cool to give it a try. This terrarium was built in May 2014 and so far (October 2014) everything is doing well, so fingers crossed that it continues that way.
For this project I purchased a cheap fish tank from the second hand store for $10. I first checked that the tank was watertight then began the project. I designed the terrarium so that it would be self watering from a reservoir. This reservoir was created by filling the base of the tank with some washed quartz rocks to a height of about 1-2 inches. I have found that this holds approximately 1-2 litres of water and at the moment I seem to only need to fill it once or twice a fortnight. Next, I got some small diameter PVC pipe and cut two pieces to the same height of my rock layer. I then cut a slot at one end of the pipe and covered that end of the pipe with fly screen, using the hot glue gun to keep the fly screen in place. These pieces of pipe were then placed into the rock bed (with the end covered in fly screen at the bottom) at an equal distance apart and roughly central so that they could be used as a wick, thus allowing the terrarium to water itself. I cut another length of the PVC pipe to run from the top to the bottom and did the same as with other lengths of pipe (covering with fly screen etc.), and placed it in the back corner. This gives you a point to fill up the reservoir with water.
After the filling tube and the wicks were in place I cut a piece of fly screen to cover the entire base of the terrarium. I allowed the fly screen to travel up the sides of the terrarium a couple of inches so that I didn’t get the soil falling down the sides into the reservoir. I cut a hole in the fly screen just above each wick and then filled the wicks up with the soil medium. I then packed out the sides of the terrarium so that the fly screen did not move and then I filled up the terrarium with the rest of my soil. For my soil medium I used a 50:50 mix of peat moss and washed sand. I rinsed the medium with my garden hose until the run off was clear then I rinsed it with some demineralised water and placed it all into the terrarium.
To build the light box I got a sheet of ply board and cut 4 pieces the same length of each side of the terrarium then just put an angle on them and glued them together with a hot glue gun. Initially I used only one light globe but I thought it was a bit dark so I upgraded to two globes. I now have the terrarium running with two 24w cfl daylight globes from Bunnings. They seem to be doing well with growth at the moment. I run the lights for a 14 hour photoperiod. On the inside of the light box I glued some aluminium foil to the sides so that the light is reflected down towards the plants.
I purchased 2 cephalotus plants to put into the terrarium. To prepare them I placed both plants into a tub of water to wash all the soil off. I was then able to separate some divisions from the plants. I found that I had 2 large plants and 1 small plant with a good root system and 1 medium sized plant that unfortunately had no root system at all. The three plants with roots I planted into the terrarium straight away.
The plant division without roots I decided to plant into an indoor mini greenhouse that I had bought previously at Bunnings for $10. Before I did this though I had heard that it was possible to grow new plants from pullings of leaves and pitchers. So before I planted the division without roots I was able to pull away from its main body 2 pitchers and 2 leaves. I then potted this division without roots and these pullings into a pot containing 70:30 peat:sand and placed it inside my mini greenhouse. The mini greenhouse was set up on a heat mat (set at 30°C) and sat underneath two 600mm fluoro (daylight) tubes. After 2 months in the mini greenhouse the plant division that had no roots still looked the same. Of the pullings that I had taken there was one pitcher and one leaf that had remained green and I could see a few very tiny leaves starting to push up from the soil. I decided it was time to transfer these new plants to the terrarium. While transferring them I was happy to find that the plant division that previously had no roots had grown quite a good root system.
While I was in the mood I decided to re-pot my first cephalotus plant that I acquired in January. While repotting it I was able to divide it and remove a small plant with quite a large root system and put it into the terrarium as well. Now I have 7 cephalotus plants growing quite happily in the terrarium.
When I first built the terrarium there was no ventilation at all. I quickly found that it was extremely humid inside, so much so that you could barely really see into the terrarium due to condensation covering the walls. I decided to install some ventilation after this in the form of a small 8cm computer fan mounted on the side of the light box which I powered by an old mobile phone charger. At first I had the fan running at the same period that the light was on. Doing this I found that the terrarium became dry and the water in the reservoir was disappearing in about 2 days so I altered the time that the fan ran by putting on a separate timer for the fan. I made it run for approximately an hour a day but I found that it actually did get quite warm in the terrarium so I recently changed the timing of the fan so it now runs for 15 minutes every 2 hours except at night when I don’t have it running at all.
I have recently measured and found that during the day (when the lights are on) the temperature of the terrarium sits around 24-25ºC and when the ventilation fan runs (for 15 minutes every two hours) the temperature drops down to 22 ºC. At night the temperature drops down to around 17-18ºC. Obviously this temperature will vary depending upon the temperature inside my house. It will be interesting to see what the temperature gets up to in the summer when my house heats up like an oven.
Early on I had an issue with powdery mildew forming on one of the Cephalotus. I have since treated the powdery mildew with wettable sulphur and I now ventilate the terrarium and this seems to be stopping the powdery mildew from forming.
All in all I feel this project has been quite successful and I am really happy with the way it looks sitting on my kitchen bench.