Building an Orchidarium

http://www.pumpkinbeth.com/2017/09/building-an-orchidarium/

I love indoor creating bottle gardens, terrariums, vivariums, orchidariums, and other indoor gardens.  In this article I’ll show you how one of my orchidariums was created.  I hope this feature will help you if you’re considering creating an orchidarium, vivarium, terrarium, or other lovely indoor garden of your own.

The Glass Case

It’s entirely possible to build your own glass case, but it’s a complicated and labour-intensive process, which I decided to avoid on this occasion.

There are a large selection of new and second hand, pre-built vivariums available for sale, many of which have been designed and marketed for keeping dart frogs, geckos and chameleons in, happily most of these terrariums are also suitable for growing plants inside.

On this occasion, to create this orchidarium, I opted for an ExoTerra Natural Terrarium Medium/X-Tall, which you can see pictured below.

A photo of the Exo Terra terrarium
The ExoTerra Natural Terrarium Medium/X-Tall. The terrarium measures 60cm x 45cm x 90cm (W x D x H) and comes with a wire mesh lid, opening doors, air vents and cable guides. There is also a natural looking polystyrene backdrop which I have removed in this photo.

This ExoTerra Natural Medium/X-Tall Terrarium is 90cm tall, 60cm wide, and 45cm deep, which is the perfect size for the location where it will be placed.  This ExoTerra Terrarium was supplied by Northampton Reptile Centre.  The people at the Northampton Reptile Centre were friendly and helpful – my first terrarium arrived with a crack across its rear glass panel, happily the Northampton Reptile Centre sent me out a replacement terrarium which arrived the following day.

This ExoTerra Natural Medium/X-Tall Terrarium, features lockable glass doors, a ventilation panel at the front, a sealed water-tight area for a reservoir at the base of the terrarium, as well as cable guides for any electronic equipment, a removable wire mesh lid for ventilation at the top, and slightly raised feet (useful if you want to place a heat-mat under the case).   This terrarium also comes with a polystyrene, rock-effect backdrop, which I decided not to use on this occasion.

Creating a False Bottom

It’s important that this orchidarium offers a humid environment, with excellent growing conditions for the orchids that I wish to grow inside.  I plan to line the bottom of this orchidarium with cushion moss.  I decided to use what is known as the ‘false bottom’ technique – where a raised platform is used to support the main landscape of the terrarium, with a reservoir of water underneath.

The simplest way to create this false bottom is to use plastic grids, which are known as ‘egg crate’.  Egg crate can easily be cut to size with a sturdy pair of scissors.  Egg crate is available from aquarium suppliers, although I found mine on eBay.  Each egg crate panel has lugs and slots, which allow them to be combined to construct a larger area.  By adding upright panels around the sides, I constructed a ‘basket’ shape made of egg crate, which will hold the compost.  To build the basket, I used zip-ties, which are strong, quick, and simple to use.

The egg-crate basket, with pipe feet to raise it up and create a reservoir.

The egg-crate basket is raised up off the base of the tank using short lengths of plastic plumbing pipe, also attached to the egg-crate with zip-ties.

Detail of egg-crate used in terrarium construction
Egg-crate basket detail showing zip-tied construction of the basket and pipe feet

Please note that it’s important to drill a few holes around the base of the pipes, so that any water within the reservoir can move freely in and out of the pipes – this is to prevent the plastic pipes filling up with stagnant water, which might encourage a build up of unwanted conditions at the base of the orchidarium.

Drilled pipes used to raise the egg-crate basket
Egg-crate basket detail showing drilled holes in the pipe feet to ensure water can circulate and does not get stagnant.

Once complete, the basket is ready to position in the tank.

The completed egg-crate basket.
The egg-crate basket in position. You can see the space below it which will stay as a water reservoir.

The next step is to ensure the compost and moss will remain moist.  I lined the basket with a piece of landscape fabric, then I laid capillary matting over the top.  I ensured that the capillary matting had long over-hangs, these overhangs will drape down into the water reservoir below, taking up water, to moisten the compost above.

The basket lined with landscape fabric and capillary matting, which drapes down into the reservoir.

The capillary matting isn’t a beautiful feature, so I added a screen of black landscape fabric around the sides of the base of the orchidarium, to improve the aesthetics.  The dark colour of this landscape fabric will also help to reduce the amount of light entering the orchidarium’s water reservoir – this will help to prevent the build-up of algae at the base of the orchidarium.

At this point, I also inserted a small plastic tube, through the landscape fabric, down into the reservoir – this is to ensure that I will have the option to easily drain the reservoir, and replace the old water, with fresh rainwater when necessary, without having to dismantle the entire base of the orchidarium to do so.

The drainage pipe for replacing the reservoir water. You can also see the ventilation holes at the base of the doors of the Exo Terra terrarium.
Detail showing the drainage pipe which can be used to drain the water in the reservoir, if it needs replacing.

Constructing the Landscape

With the basics of the orchidarium now in place, the next stage is to landscape it.  It’s possible to create all kinds of original, complex, and attractive landscapes within a terrarium – some people use rocks or branches which have been siliconed to the back and sides of the terrarium.  Another option is to use expanding foam, which can be sculpted to your own design, and then covered with coir compost and moss to create an attractive backdrop for the orchids.  I decided not to add any permanent fixtures at this stage, which allows me the opportunity to change things, should I wish to.

I purchased some large, sculptural pieces of cork bark from Porters Foliage in New Covent Garden Market, which I cut to size to fit inside this orchidarium.  I used an extra piece of egg crate to support the cork bark, and prevent the cork from damaging the capillary matting or landscape fabric below.

Detail of the base of the cork bark sculpture on egg-crate.
Positioning the cork bark within the terrarium.

I positioned large pieces of flat, cork bark at the back of this orchidarium, to provide a backdrop to the cork and plants in front.  This cork will provide additional locations to mount orchids inside this orchidarium.  I then filled the egg crate basket at the base of the orchidarium with coir compost, I positioned cushion moss on top, to create the base of the landscape for this orchidarium.

The Orchidarium with the cork and moss in place. The first orchids, a selection of restrepias, have been mounted.

Lighting

I chose LED lights, which produce a good colour temperature for plants, with light that is around 6500K – and is very similar to natural daylight.  LED lights use very little power, and produce almost no heat as they operate.

I opted to use the Advanced LED Lighting System by Jungle Hobbies.  These lights have a built-in timer, and are programmable with 5 light stages (dawn, sunrise, daylight, dusk, sunset) this gives a good range of light levels and colour temperatures throughout the day.

The Jungle Hobbies Advanced LED Lighting System.
The Jungle Hobbies Advanced LED Lighting System – showing the clock at one end of the light.
The Jungle Hobbies Advanced LED Lighting system can be controlled and programmed by a handy remote control.
The Jungle Hobbies Advanced LED Lighting System. This picture was taken with the lights in ‘sunset’ mode – the main white LEDs are dimmed, and supplemented with a range of coloured LEDs to give a warm evening glow.

Humidity and Ventilation

The Exo Terra terrariums come with a wire mesh lid, this provides an opening for airflow circulation and air exchange within the terrarium.  It’s important to have good air circulation and to allow for air exchange within the terrarium, but having such a large, open entrance and air exchange area has drawbacks, resulting in the humidity levels dropping at a fast rate, which is not good for the moss and the orchids I plan to grow inside – most of which would prefer to be at 60-70% RH (relative humidity).

To prevent the humidity levels dropping so quickly, I initially looked into having a glass lid made for this orchidarium, but this was prohibitively expensive.  I then found a company, Aquarius Plastics, that were able to cut and polish a piece of 6mm clear acrylic to the right size and shape to fit the top of the orchidarium.  The design for the lid includes:

  • Notches in the rear corners to allow cables/pipes in and out.
  • Notches in the front corners to accommodate the curve of the door hinges.
  • A square hole to seat the external ventilation fan.
  • A round hole which is currently plugged, but I may use in future if I set up a fogging unit to improve humidity.
The replacement lid for the ExoTerra tank – a piece of 6mm clear acrylic, cut to shape, with fitment holes for the MistKing misting system nozzles, and notches at the corners for the cable guides and front hinges. The square hole is for the external fan, and the round hole allows me to add a fogging unit in future, should I wish to.

Orchidarium fans

Ventilation in the orchidarium is essential.  It’s important to have air movement within the orchidarium, as well as air-flow into and out of the orchidarium.  To achieve this, I’ve installed two fans:

  • An external fan sited in the acrylic lid – this will push air out of the top of the glass tank, and by doing so will draw fresh air in through the ventilation holes in the bar across the front (just below the doors).
  • An internal fan in the top corner of the tank, which will circulate the air within the orchidarium and ensure consistent humidity throughout the entire tank.

I purchased two small, quiet, cooling fans made by AC Infinity – but any small computer fan would be suitable.  The fans are powered via USB cables, and can be daisy-chained, so only one power adapter is required.  They also have individual speed switches with low, medium, high, and off settings.

The internal fan will run constantly, moving the air around inside the orchidarium and ensuring a consistent humidity level in all areas of the tank.  Choosing how often to run the external fan, to draw in new fresh air, is more complex – as any new air pulled into the orchidarium will result in the humidity dropping.  I decided to manage this by connecting it to a Hygrostatic controller – which will run the fan when there is plenty of humidity, but ensure that if the humidity drops below, say, 75% RH, the external fan will switch off – thereby preserving the humid environment for the plants.

The interior fan used to circulate air within the terrarium. The fan is attached to the glass by small suction hooks.
The two fans in position, one cut into the acrylic lid to allow external air exchange, and the other for internal air circulation and movement.
The external circulation fan which drops into the hole in the acrylic lid, and allows air to be moved out of the tank, drawing fresh air in through the front ventilation holes just below the doors of the ExoTerra terrarium, providing good air exchange within the terrarium.

Misting System

For this orchidarium’s misting system, I chose to install the MistKing Misting System (which is also produced by Jungle Hobbies).

The MistKing Ultimate Misting System is a starter pack with everything you need to set up an automatic misting system for a terrarium.

There aren’t many MistKing suppliers in the UK.  Jungle Hobbies have an EU office, and so were able to ship the lights and misting system to me within a couple of weeks.

Setting up the misting system for the first time is very straight forward – the instructions are very clear.  The plastic pipe just pushes into the fittings for the pump and misters – although while testing this for the first time, I found that a couple of the connections didn’t have a watertight connection, which left me with a puddle of water.  Simply pushing the pipes further home to make a proper, watertight connection solved this problem.

The MistKing pump. The unit on the left is the DripZip which maintains pressure and allows the system to run with circular flow, giving immediate water pressure at the misters when the pump activates. To keep things neat and tidy, I’ve put the pump and power adapters into a box with notches cut out for the cables and pipes. Another option is to put them inside the cabinet, or stand, on which the terrarium is placed.

The misting system comes with a good timer which can be programmed to automatically mist the tank at various times throughout the day.  It’s also possible to control the misting system with an alternative hygrostatic controller to maintain a particular humidity range, if you want.

The MistKing seconds timer, showing the current time, and the next misting programme. The misting system can be activated manually by holding the ‘up’ button for five seconds.

The misting system doesn’t come with a water reservoir, so I have used a black bucket with a lid (which will keep the dust and light out).  Fitting the bulkhead to the bucket is very straightforward.

A simple bucket with a lid, drilled to fit the bulkhead, makes a great reservoir for the misting system.
Detail showing the bulkhead fitted into the bucket through a small hole. This allows the pump to be gravity-fed, ensuring the pump primes itself quickly each time it runs.
The three MistKing misting system nozzles fit through the custom-drilled holes in the acrylic terrarium lid, and can be directed to form a fine mist cloud across the entire tank.
Each MistKing misting nozzle produces a fine mist of 50 micron droplets.

Here is the orchidarium filled with orchids, mosses, and ferns.  It’s not entirely finished yet, I have some tweaks I wish to make, but thought I’d show you what this orchidarium looks like now.

The orchidarium, fully planted with miniature orchids and some ferns.

Restrepia purpurea ‘Rayas Vino Tinto’, pictured inside my Orchidarium.
This Orchidarium is planted with ferns, mosses, and orchids.