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What does that mean?

(An explanation of some of the words and terms used in the hobby, or on this website)

A Brief Discussion on Lighting

Why fluorescent lighting for dart frogs, and what are all those different types of bulbs anyway?

First, the different types of light bulbs…

Incandescent bulbs are the inexpensive bulbs we have all been using in our overhead lights around the house. They are shaped like a pear more or less. They operate by running electric current through a wire in the bulb, getting it white hot, producing light and heat. They come in a variety of wattages or power levels. These bulbs do not work well for dart frogs, they produce too much heat, and the lighting color is generally not that pleasant looking on a terrarium.

Fluorescent bulbs are the long ones like they have in the ceilings of most stores. These bulbs are filled with vapor, which is excited by the electrical current and then glows, producing light and some heat. Four foot is a common length for these, and you will often see them in homes in “shoplights”. These bulbs are made in a variety of lengths and wattages. Fluorescent lighting is much more efficient than incandescent lighting, that is, a higher percentage of the electricity that goes into the bulb becomes light, as opposed to heat, when compared to incandescent. Fluorescent lighting is available in different colors, which can create different effects. I recommend bulbs which are designed to mimic the light of the sun. These lights are a bright crisp white with a slight blue cast. Hardware stores will stock four foot lamps called “Daylight Deluxe” or similar names, for a reasonable price.

In the past few years Power Compact Fluorescent bulbs have become very popular, noted for producing more light for less watts. They come in two configurations, the first being the “squiggly” type, that are in the same shape as an incandescent bulb, and can be screwed into a standard lamp holder. These are a great replacement for incandescent bulbs, they produce a lot of light with the watts they use, but they do not really compare to the second type of compact fluorescents, the linear format, or long tubes. These are usually a paired or twin tube fixed to a plug on one end, where it plugs into the fixture. These generally are used with reflectors, and are can offer similar light output as smaller metal halide bulbs, for less money and less heat.

And we would be remiss if we did not touch on full spectrum lighting. Full spectrum lighting refers generally to lighting which attempts to be similar to the effects of natural lighting, offering a spectrum of wavelengths that span much of what the sun puts out. Some reptiles and a very few amphibians need some of these wavelengths for good health, but fortunately for us, dart frogs do not require full spectrum lighting, just enough light to see their food! Neither do terrarium plants require full spectrum lighting.

Other Lighting terms

Wattage - how much power a bulb consumes, which should relate to how bright it is.

Color Rendering Index , or CRI- How close the light from a bulb comes to duplicating the suns light, on a scale of 1-100. Incandescent bulbs hit in the sixties, “Cool White” style fluorescents hit the seventies, but “Daylight” type fluorescent bulbs get into the low 90s, which makes for a very attractive lighting for a terrarium.

A more common and popular term for essentially the same thing is the Kelvin rating system. For terrarium use, I suggest lighting between six and seven thousand kelvin, or K. This is a crisp white light with a touch of blue, said to be similar to noonday sun.

Plant and terrarium terms

Bromeliad - a type of tropical plant, which occurs only in the American tropics. The plant family includes bromeliads, and tillandsias, or air plants. Bromeliads typically hold water in the pockets where the leaves come together. See picture. Bromeliads can vary in size from a little bigger than a golf ball, to the size of a car. Bromeliads grow on tree limbs, rocks, the ground, and other places. Bromeliads derive the nutrients they need from debris that falls into the water in their folds, and derives little or no nutrients from the root system, which is primarily there just to hold the plant in place.

Bromeliads often serve as habitat for a variety of rainforest creatures. Of particular interest to the dart frog community is the fact that many dart frogs will place tadpoles in the water in a bromeliad, where the tadpole will then go on to develop into a frog.

Bromeliads produce a variety of flower types, some showy and some not. The leaves of many bromeliads can be brightly colored. Bromeliads can be grown from seed, but most plants will form “pups”, either as an ongoing process, or as the “mother” plant dies. Bromeliads typically require fairly high light levels to succeed. A common bromeliad is the pineapple, which is the only bromeliad with an edible fruit.

Tillandsia - Tillandsias are in the same family as bromeliads, but prefer things dryer than broms. Tillandsias generally have no pitchers or spots for water to accumulate, but instead are often covered in hairs which help the plant collect moisture and shield the plant from the sun. They like bright lights and need to dry out every day.

Epiphyte- A type of plant which can grow on a “non soil” substrate, such as a tree or a rock. These plants are not parasites, but will root onto the surface they are growing on. The roots are for support generally, and while the plant may derive nutrition through the roots, the plant is not parasitic.

Drip point - term describes using a thin tube attached to a submersible pump to direct water to a spot in the tank, typically on the back wall. This will allow many plants to grow vigorously on such spots. Small vines will rapidly cover such areas of the back wall, and many epiphytic orchids will grow well on such spots. When setting up a tank from scratch you can hide the drip tubes behind the background, and stick them through it from behind. Tree fern panel is often used for the background in tanks with drip points, but cork bark or other types of backgrounds can work also.