Vivarium Construction 102
Vivarium Lighting 101

Everything you need to know about illuminating a vivarium!

 
 

Intro To Vivarium Lighting

Selecting lighting for your vivarium can be daunting at the beginning. There is so much information about lighting online, that it can be difficult and confusing to figure out just how much, and what type of lighting you need. This article will explain both the basics and more advanced aspects of what should be kept in mind when selecting the lighting for a vivarium. Everything from inexpensive compact fluorescent bulbs to the higher-end LED fixtures are described, with PROs & CONs listed for each style. Whether you are building a commercial exhibit, or just a nice little desktop vivarium for your home or office, this article should help steer you straight.
 
Before we can get too far into which types of should be considered, we'll discuss the basic lighting lingo that will be used to help figure it all out.
 

Lumens

A rating of how bright the source will appear to the human eye

Lumens Vivarium Definition A lumen is the unit of measurement for the total amount of visible light emitted by a source. Most bulbs are rated for lumen output (often abbreviated as "lm") by the manufacturer, to notify the consumer of how bright a bulb will appear to the eye. If there are two 1000 lumen rated bulbs in a fixture, the total luminous emittance will be approximately 2000lm, as lumen amounts add-up for multiple bulbs. The term for metering how much light is incident on a surface is called illuminance, which means lumens per square meter. (lx for short) Lumens & illuminance are very important in vivarium building because these measurements will help us determine whether or not a display will look sufficiently bright enough to human eyes.
 
A simple analog or digital light meter is a useful tool for spot-measuring illuminance in a live vivarium. Knowing exactly how much light is incident on a surface can help compare your vivarium to others, using an "apples-to-apples" unit of measurement that's commonly used in the hobby. Because the amount of measurable light will differ considerably from the top of an enclosure to it's substrate-level, it's important to measure both for an accurate assessment.
 

Kelvin (Color Temperature)

A rating of how the light source will represent color within the vivarium

Kelvin Simple Definition Kelvin is the unit of measurement for the overall color temperature of a bulb. Unlike the lumen unit of measurement, Kelvin ratings do not add-up. (If you use two 5000K bulbs, the Kelvin rating remains 5000K) Kelvin helps us to determine whether or not the enclosure will look natural to the human eye under a certain light source. When selecting a vivarium light bulb, we suggest finding one in the 5000-6700K range, since natural daylight spectrum is 5500-6500K (depending on viewing standards). In our experience, all fluorescent and LED bulbs in the appropriate color spectrum will grow all commonly available vivarium plants with ease, assuming the bulbs are bright enough for an enclosure's size. Bulbs in the range of around 5000K appear warmer to the eye, whereas bulbs rated much above 6700K can look colder. The combination of measured illuminance and color temperature are suitable measurements to help determine which bulbs you'll need to make your vivarium appear beautiful to the eye, as well as give the builder a general, but effective idea of whether or not plants will be able to thrive in a vivarium.
 

PAR & Spectral Energy Distribution

Vivarium PAR Light

A measurement of how much of the light will be usable to plants

PAR (Photosynthetically Active Radiation) values are the most accurate & effective unit of measurement to determine a bulb's efficiency in growing a plant specifically. PAR measures the spectral range of radiation from 400-700 nanometers, which is the same range plants utilize for photosynthesis. This unit of measurement is frequently used in both agriculture and the aquarium hobby, since reefs and certain underwater plants require a significantly higher PAR rating than any common vivarium plants will for long term success. As time moves on, more bulbs may be available to the vivarium building community that include relevant PAR ratings, but at the moment this unit of measurement is still fairly uncommon to the hobby. A Digital PAR Meter can be used to determine photosynthetically active radiation levels at different heights within an enclosure.
 
While PAR is the best gauge to determine how efficiently a light source will grow plants, it's not the a suitable method to determine which bulb will work best for your vivarium, since visible, naturally accurate light is critically important to the look of the finished product. For example, many agricultural & aquarium lights that have excellent PAR values would look unnatural if applied to a vivarium, due to the extremely high intensity of blue & red visible light within the 400-700NM wavelength. To determine how accurately a bulb will make things appear to the human eye, we'll have to keep color temperature in mind as we turn to color rendering index.
 

Inverse Square Law

Inverse Square Law Applied To Vivarium Height

A critically important concept relating to enclosure height vs. lighting requirements

The inverse square law applied to vivarium lighting is important because every time the distance from a light source doubles, the light is distributed over a significantly larger area. For example, if a light source meters at 1000lx from 12in away, it's likely to only meter 250lx at 24in away, just 111lx at 36in away, and a dismal 62lx at 48in away. In other words, if "X" amount of light is needed to look great & grow plants in a 12in tall enclosure, we'd need a 400% brighter light source to produce the same amount of measurable light at the bottom of a 24in tall enclosure! Understanding the inverse square law's effect on light over a distance is critical when working with taller vivariums, in our experience. In plain English, taller vivariums require exponentially more light than shorter ones.
 
For enclosures which are under 13in tall, we typically can't recommend a bright LED option, since it's simply too overwhelming for such a short enclosure. Vivariums 13-24in in height have a wider range of lighting options available to them, from inexpensive fluorescent bulbs to higher-end LEDs. For enclosures taller than 24in, we usually recommend a more powerful LED lighting solution instead of T5HOs or other fluorescent lighting, since LEDs project better over long distances. When dealing with fluorescent lights of any kind, selecting a light fixture with a good reflector is critical. Since most LED lighting is unidirectional, a good reflector isn't as important as it would be when using omnidirectional fluorescent bulbs.
 
We break down many suggested lighting types by enclosure height later in this article, after describing the benefits & drawbacks of each type of lighting.
 

Ultraviolet / UVB Lighting

UVB Spectrum

A source of energy which assists some animals in naturally synthesizing vitamin D3

Ultraviolet B light is a type of radiation which assists many species in the natural creation of vitamin D3. Vitamin D3 assists in strengthening bones, metabolizing calcium, and helps prevent certain problems associated with keeping reptiles in captivity. Outdoors, UVB light is naturally produced by the sun, so when a diurnal species is introduced to a life in captivity, UVB supplementation may become necessary.
 
In many cases, a species can absorb D3 with a properly supplemented diet, and the expense of UVB light can be avoided. These species include many nocturnal species, but also many diurnal animals which aren't exposed to much direct sunlight in their natural habitats. If a species can't absorb D3 through it's diet, UVB lighting should be provided.
 
There are an impossibly large number of species which do require UVB supplementation... Far too many to fit into our Vivarium Lighting 101 article! Check out Exo Terra & Zoo Med's UVB lighting requirement links, to see if your animal(s) require supplementation. (External links)
 
UVB's light spectrum is 290-320nm, which is below what humans see as visible light. Because plants absorb light energy in the range of 400-700nm (PAR light), UVB lighting is not beneficial to growing plants inside a vivarium. The myth that UVB light is necessary to grow plants was likely started by businesses selling UVB lighting, which lead to ill-informed hobbyists recommending the same on forums & even at reptile expos. The only time UVB becomes necessary in a live vivarium is if the inhabitant species requires it.
 
Important: UVB does not penetrate glass lids. Always position ultraviolet bulbs over screen portions of an enclosure to ensure UVB can reach your inhabitant!
 

Color Rendering Index & "Full Spectrum" Light

A method of determining how accurately a light source will display an object

Often referred to as "color accuracy", CRI is typically measured from 0-100 percent; indicating how accurate a light source is at displaying colors compared to a reference light source of a similar color temperature. Many manufacturers include CRI rating information with bulbs, making it a fairly usable gauge of how natural things will appear to the human eye, if the correct color temperature is used. Because CRI is completely independent of color temperature (kelvin), it's important to first select a bulb in the appropriate color temperature range before considering CRI. In other words, a 4000K bulb may have an 80+ CRI rating, but would appear too warm, and would not be the correct color spectrum of light for a vivarium. (Between 5000-6500K is ideal, as explained above) The term "full spectrum light" is used often used in marketing terms these days, essentially meaning a bulb emulates natural light. (Or in plain English, it's got a "good" color rendering index!) If a bulb is labeled as "full spectrum", but doesn't include it's exact CRI, that often indicates the bulb likely has a fairly high (80+) CRI. Anything in the 80+ range is considered to have a good CRI, and bulbs rated 90+ have an excellent CRI.
 

Overview Of Different Lighting Types

Common Vivarium Lighting Types With all the lingo explained, this next section will discuss many of the most common bulb types used in the vivarium hobby. Each has it's own good & bad points, which we'll outline in detail. With so many new styles emerging so rapidly, we'll do our best to keep this section of the article as up to date as possible. (Last updated 8/15/15)
 
Vivarium CFL Bulb

Compact Fluorescent Bulbs

 
Compact fluorescent (CFL for short) bulbs are available in a very wide range of shapes, sizes, wattages, and color temperatures. Most sizes easily fit into the most inexpensive (and common) light housings. Finding a fixture for this type of bulb is a cinch, as they'll work in a wide variety of common hood types. The main disadvantage to a CFL is heat, so those working with heat-sensitive species should keep this in mind. Most possible heat issues found when using higher wattage bulbs can be controlled by using deeper light fixtures to keep the bulb further from the enclosure. We've also used rubber feet purchased at a hardware store to lift a fixture a little higher from the top while keeping it looking neat. Hanging the lights above the terrarium works great, but admittedly it's at the cost of aesthetics.
 
Compact fluorescent bulbs average roughly 60-70 lumens per watt.*
 
We'd suggest using CFLs when working with non-temperature sensitive species, with vivariums ranging from 8-36" wide. (At 48" wide, tube-style fluorescent fixtures are a better bang for your buck!) A good reflector becomes more important with taller enclosures (20"+), as reflecting a CFL's light downward is critical for these bulbs to perform well. Due to the bulb's very wide omnidirectional lighting pattern, we don't recommend this option for enclosures over 24" tall. Due to the price, long-standing use in the hobby, and compatibility with both Exo Terra & Zoo Med fixtures, we include Plant Growth CFLs and Exo Terra UVB CFLs as options in many of our NEHERP Vivarium Lighting Kits, and complete vivarium kits.
 
CFLs benefit from a fixture that will reflect as much light as possible, while allowing heat to escape the fixture to keep temperatures down within the vivarium. Good fixture choices for screw-in lights include Exo Terra Compact Tops, Zoo Med Terrarium Hoods, Zoo Med Deep Domes, Exo Terra Polished Domes, and standard "clamp lamps". Higher-wattage compact fluorescent bulbs can be too long to sit flush in a standard clamp lamp, so be sure you choose a fixture that's deep enough if you'll be using a 23W+ CFL.
 
CFLs we carry & recommend: Generic Plant Growth CFLs | Horticultural Plant Growth CFLs | Exo Terra Natural Light CFLs | Exo Terra UVB CFLs | Zoo Med UVB CFLs
 
Advantages of CFL Bulbs
The most inexpensive option
Widely available online & in local shops
Available in a wide range of brightness
Available in a wide range of color temperature
Can be used in the least expensive fixtures
Available with or without UVB output
Disadvantages of CFL Bulbs
Produces a considerable amount of heat
Not very efficient: Low lumen/watt ratio
Bulbs over 26W won't fit standard housings
Not suitable for enclosures over 24" tall

 
 
Vivarium Fluorescent Tube Bulbs

Fluorescent Tube Bulbs

There are three types of commonly used tube fluorescent bulbs. In order of most efficient to least efficient: T5HO, T8, and T12. The number following the "T" is a designation of width, by 1/8 inch increments. (T5 = 5 eighths / T8 = 8 eighths / T12 = 12 eighths) These bulbs have some of the widest ranges of availability for sizes and color temperatures. Each bulb type comes in a few different lengths and wattages ranging from 12" all the way up to eight feet for commercial applications. Bulbs of the same length & style are generally the same rated wattage, in the herpetoculture hobby. (So any common brand of 24" T8 bulb we offer will fit any 24" T8 fixture we offer + so on.)
 
T5 bulbs produce ~95-100 lumens per watt * / T8 bulbs produce ~75-80 lumens per watt * / T12 bulbs produce ~55-60 lumens per watt *
 
Standard "tube" fluorescent bulbs are most commonly used with wide enclosures, when placing many terrariums in a row, or with "rack style" breeding setups. For those situations, fluorescent lighting is often the most cost effective long-term solution, when an average/moderate amount of heat isn't a concern. Although each style of these bulbs are available in a wide range of lengths, the 24" and 48" widths of bulbs & fixtures are by far the most common & cost effective. Inefficient T12s are occasionally used (and work fine for shorter enclosures), but are being phased out by many manufacturers as the style is replaced with newer tech. Nowadays, the least efficient bulb most enthusiasts use is a T8, with T5HO being the best bet in most situations.
 
Any of these bulbs (T12, T8, T5) require more expensive housings than standard screw-in bulbs. We don't recommend spending too much of the lighting budget for just a fixture, but cheap (hardware-store) non-reflective fixtures aren't a good choice either. As much light as possible must be reflected downward into your vivarium for the best results. A white reflector won't reflect as much as a mirror-polished one, and cheap housings with black reflectors should be avoided. Ballast types are important when choosing a fixture for a tube fluorescent! Super inexpensive magnetic ballasts don't last as long, produce more heat, and can create an annoying hum or buzz sound. Electric ballasts last longer, produce less heat, and don't hum (as badly). Most fixtures are labeled with a ballast type, so keep that in mind when choosing which is best for you.
 
Tube Fluorescent Bulbs we carry & recommend: Horticultural Plant Growth T5HOs, JumpStart T5HOs, Zoo Med Reptisun T5HOs and Zoo Med Reptisun T8
 
T5HO - Thinnest Width (5/8") - Most Efficient
Advantages of T5HO Bulbs
Decent availability
Most efficient fluorescent bulb
Available in many lengths
Available in many color temperatures
Brightest fluorescent bulb
Excellent choice for breeding racks
Available with or without UVB output
 
Disadvantages of T5HO Bulbs
Most expensive fluorescent bulb
Hottest fluorescent bulb Bulbs/fixtures other than 24" & 48" are expensive
 
T8 - Medium Width (1") - Average Efficiency
Advantages of T8 Bulbs
Available Everywhere
24in & 48in sizes are very inexpensive
Available in many color temperatures
Available in many lengths
Good efficiency rating
Excellent choice for shorter breeding racks
Available with or without UVB output
 
Disadvantages of T8 Bulbs
Bulbs/fixtures other than 24" & 48" are expensive
Bulbs produce an average amount of heat
Not recommended for enclosures over 18" high
 
T12 - Wide Width (1.5") - Lowest Efficiency
Advantages of T12 Bulbs
Least expensive tube fluorescent bulb
Available everywhere
Available in a wide range of color temperature
Available in many lengths
Available with or without UVB output
 
Disadvantages of T12 Bulbs
Least efficient fluorescent tube option
Produces an average amount of heat
Not recommended for enclosures over 14" high
Being phased out due to inefficiency
Large bulb width less convenient to use on racks
 
T5HO - Thinnest Width (5/8") - Most Efficient
 
Advantages of T5HO Bulbs
Decent availability
Most efficient fluorescent bulb
Available in many lengths
Available in many color temperatures
Brightest fluorescent bulb
Excellent choice for breeding racks
Available with or without UVB output
Disadvantages of T5HO Bulbs
Most expensive fluorescent bulb
Hottest fluorescent bulb Bulbs/fixtures other than 24" & 48" are expensive
 
T8 - Medium Width (1") - Average Efficiency
 
Advantages of T8 Bulbs
Available Everywhere
24in & 48in sizes are very inexpensive
Available in many color temperatures
Available in many lengths
Good efficiency rating
Excellent choice for shorter breeding racks
Available with or without UVB output
Disadvantages of T8 Bulbs
Bulbs/fixtures other than 24" & 48" are expensive
Bulbs produce an average amount of heat
Not recommended for enclosures over 18" high
 
T12 - Wide Width (1.5") - Least Efficient
 
Advantages of T12 Bulbs
Least expensive tube fluorescent bulb
Available everywhere
Available in a wide range of color temperature
Available in many lengths
Available with or without UVB output
Disadvantages of T12 Bulbs
Least efficient fluorescent tube option
Produces an average amount of heat
Not recommended for enclosures over 14" high
Being phased out due to inefficiency
Large bulb width less convenient to use on racks
 
 
Vivarium Screw In LED Bulbs

Screw-In LED Bulbs

With the highest efficiency rating, low heat output, and best price of of any LED, it's no wonder why screw-in LEDs are one of the most common solutions for illuminating a vivarium. Advantages over fluorescent bulbs include a lower temperature (actual temperature, not color temperature), significantly better efficiency, and an overall brighter output. In many cases, the screw-in LEDs allow for the use of matching-brand light fixtures. Higher quality LEDs produce very little heat in comparison to all other lighting types, and are most commonly unidirectional. Traditional Jungle Dawn vivarium-specific LED bulbs have a combo of two different color temperatures, high quality LED diodes, and are a great value considering their performance. Jungle Dawn LEDs were the 1'st screw-in vivarium LED bulb in the USA. They are our favorite screw-in LED due to the low heat output, low wattage, bright light output, and ideal color temperature. Since they are unidirectional & available in a wide variety of sizes, they are well suited for any terrarium ranging from 12" to 36"+ high. Due to the price, performance, and reliability of these, Jungle Dawn LEDs are one of the the lighting options we include in our NEHERP Vivarium Lighting Kits, and complete vivarium kits.
 
Traditional Jungle Dawn LEDs are available from 9W to 22W, and are horizontally oriented when screwed in. This style of bulb is most commonly used with Exo Terra Compact Tops (from 8-36in wide), Zoo Med Terrarium Hoods (12-36in wide), and in custom fixtures. When using screw-in LEDs, it's often a good practice to remove the metal reflector in the hood. This will allow heat to escape better, which will extend the life of an LED unit & keep temperatures down within the enclosure. This style of bulb makes a great choice for enclosures ranging in height from 12in to 36in, and is available in 9W, 11W, 13W, 17W, and 22W models.
 
Jungle Dawn Grow & Glow LEDs are specialty bulbs with added red & blue spectrum PAR light diodes, designed to be added as supplement light for plant growth. Available in 15W and 20W models, either are best used over larger enclosures where an added boost of PAR (plant) light would be beneficial. These Grow & Glow LEDs are so effective at growing plants, we use quite a handful in our indoor greenhouse, growing NEHERP plants!
 
The Jungle Dawn Mega Spotlight is the newest & most powerful model, and produces an incredibly bright beam of light. Unlike the traditional Jungle Dawn LEDs, this is vertically oriented when screwed into a fixture. Very high PAR, Lumen, and CRI ratings are paired with a 6500K color temperature to provide a natural looking solution to grow flora in even very tall enclosures. Unique features include diodes with 60º focused lenses, an internal cooling fan, an efficient aluminum heat sink, and a 40,000-hour rated life. Compatible with most standard-bulb dome style fixtures, this is an incredibly versatile bulb, and the best priced option for many taller enclosures. At a whopping 40 watts, its by far our most powerful LED bulb. Suggested for enclosures ranging in height from 28in and taller.
 
We carry & recommend all types of Jungle Dawn LED lighting including the Traditional, Grow & Glow, and Mega Spotlight models.
 
Advantages of Screw-In LED Bulbs
The most energy-efficient option
Ideal color temperature
Cooler-running option than fluorescent
Can be used in inexpensive terrarium hoods
Excellent light penetration
Extremely long diode life
Different wattages for different heights
Disadvantages of Screw-In LED Bulbs
Expensive compared to CFL
Available online only
No UVB output

 
 
 
 
Linear LED Vivarium Bulbs

Linear LED Fixtures (Hood & Diode-In One)

With the highest efficiency rating and lowest heat output of any light in the hobby, it's no wonder linear LED fixtures are quickly growing in popularity. LED fixtures are improving every day, and becoming less and less expensive as time goes on. Unfortunately prices are still fairly high compared to screw-in LEDs, but the big advantages are a lower temperature (actual temperature, not color temperature), efficiency, and brightness. Higher quality linear LED fixtures produce the least amount of heat in comparison to all other lighting types. Many brands have adjustable color temperatures, dimming features, effects, and much more. Some of Zoo Med's LED fixtures combine a UVB-producing T5HO with LEDs for the best of both worlds.
 
LED bulbs average roughly 80-105+ lumens per watt
 
There are a ton of brands available online, with a huge range of prices, brightness, and features. The vast majority of linear LED fixtures are designed for fish aquariums, and may not be suitable for live vivariums. (For fish LEDs, check to ensure color temperature is between 5000K-6700K. Higher-than 8,000K bulbs look terribly unnatural over vivariums) We've had luck with Current Satellite Plus LEDs for enclosures up to 22in tall, Jungle Hobbies LEDs for enclosures up to 48in tall, and Zoo Med's Reptisun LEDs for enclosures up to 26in tall. Once enclosures approach 36" high, the price of necessary linear LED fixtures grows exponentially, and screw-in LEDs may be a better bang for a buck. Most clients choose linear fixtures for the sleek look, ease of installation, reliability, and incredibly low heat output.
 
We carry & recommend Current Satellite Plus, Zoo Med Reptisun LED, and Zoo Med Reptisun UVB LED fixtures.
 
Advantages of Linear LED Fixtures
The most energy-efficient option
Ideal (often adjustable) color temperature
The coolest-running lighting solution
Better light penetration than fluorescent
Extremely long diode life
Average-cost units suitable for up to 26in tall vivs
High-cost units suitable for up to 40in+ tall vivs
Disadvantages of Linear LED Bulbs
Highest price per watt/lumen
Pricey to ship
High-output units are extremely expensive
Many unreliable brands with short lifespans

 
 
 
 

Keeping Priorities Straight While Choosing A Light Source

NEHERP's Vivarium In Museum Of Natural History
One of our custom setups for HMNH
A custom setup for Harvard Museum of Natural History
 

The goals we try to keep in mind when choosing a vivarium light source

We've been building vivariums commercially since 2009, and the below recommendations are the same that we follow on a daily basis. Think of this section like a flow-chart, if that makes sense... First, we'll select a lighting type which is determined by the size of the enclosure. Then, we'll select the bulb or diode style.
 

Enclosure Height Will Help Determine The Recommended Lighting Types

Because the height of an enclosure matters so much in determining how powerful (overall) a light source will need to be, we recommend starting by selecting the lighting type. Due to the inverse square law's effect on light over a distance, shorter enclosures are much easier to illuminate than taller ones. We'll go through a couple common examples, to help narrow things down...
 
Enclosures Under 18in Tall - Easy
We consider enclosures under 18in tall to be "easy" to illuminate, because even inefficient & inexpensive bulbs (T8s, T12s, CFLs) can effectively grow plants at such a small distance. Powerful LEDs may be a bit "much" on shorter (8-12in tall) enclosures, and often times CFLs or Fluorescent tubes make a better choice for this size. UVB producing bulbs are commonly available for T5HOs, T8s, T12s, and CFLs, if your inhabitant species requires it.
 
Enclosures 18-24in Tall - Average
Enclosures 18-24in tall are considered "average" for difficulty, with LEDs performing best (due to the way they direct light without reflectors), and T5HOs & CFLs being suitable 2'nd choice options. In most cases, we wouldn't recommend T8s or T12s for 18-24in tall enclosures because they aren't as powerful or effective as T5HOs & LEDs are for projecting light over this distance. If your inhabitant species requires UVB, CFL and T5HO bulbs are available with UVB output.
 
Enclosures 25-36in Tall - Difficult
Taller enclosures (25-36in) are considered difficult, and LEDs are almost always the best bet to ensure enough light can penetrate deeply into the enclosure to grow plants at substrate level. The amount of lighting necessary to brightly illuminate a enclosure this tall down to substrate level can be surprising at first, and the new Jungle Dawn Mega Spotlights are a great way to go. For species requiring UVB in this tall of an enclosure, we'd recommend either CFLs or T5HOs with higher UVB output. (Exo Terra makes a "high output" UVB200 bulb specifically for tall enclosures)
 
Enclosures 36in & Taller - Extremely Difficult
Enclosures over 3ft tall are considered extremely difficult to illuminate, and are not recommended for inexperienced hobbyists, or to anyone who isn't able to sink at least a few hundred dollars or more on high output LED lighting. Once an enclosure gets to be this tall, lighting becomes a very significant portion of the total enclosure's cost. Email us if you have questions about illuminating this tall of an enclosure, and we'll be glad to help.
 

With Lighting Type Chosen, Balance Kelvin & PAR Ratings

With the lighting styles narrowed, the next step is a balancing act to ensure that the enclosure will both look natural to the human eye & grow plants without blowing the budget. We recommend first choosing an appropriate Kelvin rating (described earlier), to ensure the enclosure will appear naturally accurate to the human eye. PAR ratings should also be considered (whenever available) to ensure the light source will grow plants satisfactorily. On one hand, considering PAR Ratings without taking Kelvin Ratings into account often leads to blue, purple, or reddish hues being cast over the otherwise natural looking enclosure. Alternatively, a bulb in the correct kelvin range without decent PAR output will look nice, but won't grow plants well. With a little effort balancing color temperature & PAR, the lighting choices should now be narrowed down considerably.
 

Making The Decision

With the above info in mind, there should be a few suitable lighting options left to consider. From these choices, it's most often a matter of personal preference & budget goals. Keep in mind that fluorescent bulbs run hotter than LEDs, if you are working with a temperature-sensitive species. When possible, a higher output choice often grows plants better & more effectively, if it's within the budget. Unless the enclosure is very large, very wide, or has unique requirements, we try to avoid using overkill lighting solutions. Considering all the most common vivarium plants are fairly easy to grow, and the fact that they'll be placed into a humid glass box with borderline-perfect growth conditions, there's rarely a need for extremely expensive lighting when illuminating most common enclosure sizes.
 

Helpful Real World Examples

With all the above lighting information in mind, we created both the chart (below), and our interactive Vivarium Lighting Kits page to help make choosing a light source as easy as possible for common vivarium sizes. Although every vivarium's requirements can vary, the options we recommend are great proven starting points for any hobbyist building just about any type of temperate or tropical vivarium.
 
Suggested Lighting Solutions For Common Vivarium Sizes Chart
 
↑ Chart tough to read? Click to enlarge & open in a new window! ↑
 

For Inhabitants Requiring UVB Lighting

If the inhabitant(s) you are housing require UVB lighting to synthesize vitamin D, you can replace one (or more) of the screw-in or fluorescent tube bulbs over your enclosure with a UVB-producing bulb. If you'll be replacing Jungle Dawn LEDs, the 9W LED would be roughly equivalent to a 13W CFL, and the 11W & 13W Jungle Dawn LEDs would be roughly equivalent to the 23-26W CFLs (in terms of light output). Due to the different materials used for ultraviolet output, all UVB bulbs are slightly dimmer when compared most "standard" CFLs of similar wattage. (Including our plant-growth CFLs!) Use whichever UVB rating is best suited to your specific species, as your inhabitant's health should come first and foremost.
 

Setting The Light Cycle

Most plants & inhabitants do best with lighting set to about 12 hours on, and 12 hours off. This can be done with a simple outlet timer. A digital model isn't required for this application, although it's nice not needing to reset timers after a power loss! During hot summer months, timers can be set to cycle to as little as 10 hours on and 14 hours off to conserve energy & reduce heat. Try not to change the cycle too often, as it can stress the enclosure's inhabitants. (If there are any) When using a timer, please keep an eye on your amp load! Overloading a cheap 5 amp timer (commonly sold at hardware stores & box stores) is a fire hazard.
 
If you are timing only a handful of bulbs, it's usually nothing to be concerned about. If you are timing a breeding room, or a series of higher wattage bulbs, be sure not to exceed your timer's specs! All brands of timer in every store in the USA are required to list amperage ratings, so check before you buy. (All of our timers are rated for 15 amps (1875W!) minimum, which is the same as the average household circuit.)
 

Tips, Tricks, and Useful Info

 
• Vivarium plants do not need UVB. The only time UVB lighting is necessary in a vivarium is if you are housing an animal that would benefit from it.
 
• Something that's often overlooked: The vast majority of terrarium plants don't grow in direct sunlight in their natural setting, so you don't need tons of light for them to thrive. Certain plants (most commonly epiphytes, in a tropical vivarium) need a lot of light to produce lots of color as it would in nature. You can do this most efficiently by mounting the plants higher in the terrarium; closer to the light source. (Remember the inverse squared law!)
 
• Lighting doesn't need to cost a fortune. Spending a ton of money on a fixture or light bulb doesn't guarantee anything besides a lighter wallet. If you have questions about lighting, ask someone who's done it before. More often than not, you can illuminate a vivarium on a fairly tight budget. Be wary of anyone suggesting T5HO or LED bulbs as an "absolute bare minimum", as the advice is often incorrect. Both are great, but try and understand the pros & cons listed above before making a purchase. Everyone's goals are different, and there are a bunch of easy ways to get the job done. Personal preference plays a big part, here!
 
• If you are concerned with heat in your vivarium and aren't sure whether to use LEDs or CFLs, test it 1'st! Most CFLs of the same wattage operate at roughly the same physical temperature, so if you have any CFLs lying around your home, you can test them in your vivarium before spending the money plant growth bulbs. If the enclosure gets too hot, you'd better stick with LEDs. If it's cool enough, you can save a little money and stick with CFLs.
 
• "What about metal halide & high pressure sodium bulbs?" Both can produce large amounts of light, but also produce extreme amounts of heat. Maybe if you are building a massive (walk-in size) vivarium, but otherwise these aren't a good choice for most average sized terrarium builds.
 
• Positioning a fan to blow over the lights can cool even very warm methods of lighting. Keeping air moving over hotter bulbs can go a long way for keeping things cool. Even a small "desktop fan" can drop temperatures in a vivarium significantly. We added 4 recirculation fans in our old (500sq/ft) breeding room that primarily used T8 and CFL lighting, and the average top portion of cage temperatures dropped a whopping 7 degrees! (Measured with an infrared thermometer)
 
• Temperatures can range 5-7+ degrees from top to bottom on taller enclosures! Don't just measure the lowest part, as it'll always be the coolest. Infrared thermometers go a long way when it comes to figuring out the exact temperature between different parts of your vivarium. Building a rack system? We suggest sticking to roughly 48" wide shelves, if possible. Both T5HO & T8 lighting in the 48" length are the best bang for your buck, compared to other tube fixture lengths. (The 4 foot length is by far the most popular size, so manufacturers are able to price them accordingly.)
 
 

Congrats - You've finished Vivarium Lighting 101!

If you have any questions at all, don't hesitate to email us!

 
 

Thanks for choosing us as your vivarium info source!

We hope you'll choose us as your vivarium supply source, too! :-)

 
Whether you'll be creating a large commercial exhibit, or simply building a quick & easy live environment for a pet Frog or Gecko, we have all the herp supplies, vivarium plants, and tons of NEHERP brand vivarium specialty supplies you won't find anywhere else. We're a family owned & operated business, and are always happy to help with 1-on-1 support. Vivariums are what we do, so if you have any questions at all, don't hesitate to contact us!
 

The Vivarium Builder

View everything you'll need for your specific vivarium size all on one page!

 

The Online Vivarium Builder
Vivarium Builder

Design your ideal vivarium online from the ground up, and view everything on one page!

Vivarium-Related Kits

 

Vivarium Substrate Base Kits
Base Kits

Packages of substrate, drainage layer media, and a screen separator for all common enclosure sizes.
 

Complete Vivarium Kits
Complete Kits

Complete, configurable "one click" vivarium kits. Available with or without glass enclosures.
 

Vivarium Lighting Kits
Lighting Kits

Lighting for specific enclosure sizes, designed around our proven LED & Fluorescent solutions.
 

Vivarium Plant Packs
Plant Packs

Discounted plant packages designed for specific enclosure sizes and animal species!
 
 

Vivarium-Related Supplies