Drip Garden II  
     
   
  This latest incarnation of the "Drip Garden" terrarium is housed in a 36 gallon tall aquarium. The homemade stand is 2x4 construction with Mahogany plywood facing. The canopy above the tank houses the single 12 watt fluorescent light. The output of the fixture is barely enough light for the plants, so shade-loving species like the Maidenhair fern are used. A single small pump (i.e. the type used for small fountains commonly found in home centers) is used to push the water up to the top of the tank. From there, the water is piped to seven smaller tubes. These tubes are placed so that the water runs down over the face of the rocks.  
   
  The newly established terrarium with plants tucked into pockets created during rock placement. A terrarium located near a window does not need artificial light, and should not be placed where direct sunlight will hit it. This terrarium was placed in a dark part of the basement to act as kind of a "night light" for the area. The light is on a timer and is set for 12 hours of light. The light, pump and timer use very little electricity compared to other aquariums. No heater is used as the room temperature never falls below 60 degrees.  
   
  Guppies were added to the approximately 10 gallons of water. Despite the small amount of water, and only using the water cleaning properties of the terrarium, the guppies produced 3 generations of babies in 3 months.  
   
  A close-up of the initial planting. The plants should fill in the available space and hide much of the rock.  
   
  Here you can see the faces of the rocks are all covered with water. This is a very important aspect of the Drip Garden. The wet surface area of the rock allows beneficial bacteria to proliferate which keeps the water "clean". The bacteria is introduced into the tank by the rock and soil, and when given sufficient nutrients (waste from the fish) and oxygen (from the air-water interface on the rock), the result is very efficient removal of harmful ammonia from the aquarium's water without using any other type of filtration or water circulation.  
   
  Maintenance on this type of aquarium is very minimal. Initially, the fish will need a pinch of fish food now and again until a resident population of microorganisms can be established. After that, the tank only needs to be "topped off" with fresh water to replace water lost to evaporation. The idea is to create a "balanced" ecosystem. Beneficial bacteria living on the wet rock keep the water clean by removing ammonia and other harmful waste products. The plants consume available nutrients (waste from the fish which is processed by the bacteria).  
 

2005 Update		  
  The light output of the 12 watt fluorescent light, while enough to light contents of the terrarium, was too low for plants to thrive. As the aquarium is located in the basement where it receives no natural lighting, I upgraded the light fixture to a 55 watt "compact florescent" lamp.  
   
  After some time of operation, I noticed some spots on the front glass panel. These were "hard" water marks caused by tiny droplets of water bouncing off the rocks. The spots are easily removed using white vinegar and a paper towel, but this brings up a good point. While I prefer removing the front panel of glass and replacing it with a piece of glass just slightly taller than the depth of the water, some splash will undoubtedly occur. Given that the room housing this terrarium has hardwood floors, I'm glad I left the aquarium in tack.  
   
 

Maintenance to date

The terrarium continues to be self-cleaning with very little maintenance. The fish are fed several times a week, and replacement water is added a couple times a month. "Gravel vacuuming" can be done when the debris begins to build up on the bottom. You'll only need to do this once or twice a year (or you could skip it all together as the debris doesn't harm the fish or plants).

  
 


General Advantages of Terrarium compared to an Aquarium

  • Less maintenance
  • Balanced system
  • No need for filters, just one small water pump.
  • Plants thrive with little to no maintenance
  • The sound of the water
  • The rich "jungle" smell
  • The display is always changing and growing
  • Much less weight than a full aquarium

Disadvantages

  • Small fish only
  • Low light plants only
  • Need for sufficient light
  • "water spots"
  • "splash"
  • Finding attractive rocks