Confused on terrarium lighting hoods

[Paul Mc]

OK, so I'm really dumb when it comes to lights though somehow I managed to figure out a good lighting system for all my tropicals in the basement. But that took years to figure out and I did not have all of you wonderful people.

I just bought the Zoo Med 12x12x18 terrarium and am now looking for lighting. I've seen all sorts of lights for use with terrariums ranging from hoods, hanging light bars to dome lamp fixtures.

My concern is that most of these fixtures are for giving ultraviolet light to the animals inside the terrarium for proper health, and many bulbs are for heat purposes as well.

Zoo Med's 12" hood says that it includes a built-in reflector and socket for heat or UVB lamps. Are these the right kind of bulbs to use for growing orchids in it? Can I use a better substitute inside of this fixture?

I think I'd really like to keep with the hood idea as it will help to keep some humidity inside, plus it would be nice if the hood actually fit - thus looking at one Zoo Med makes.

[fishmommy]

what light level are you hoping to have at what distance from the bulb?
There are quite a few options out there. I have found compact fluorescents to have good light output per watt in a shape that can fit in that footprint.
If you want to use t5's there are options for that also. I tend to use aquarium lighting for my terrariums.
Two of this T5 fixture will fit on a 12x12:
Aquarium T-5 Fluorescent Light Fixtures: Coralife Mini Aqualight T-5 Dual Lamp Fixture

I have some minature CF fixtures but I can't find them online anywhere - they may have stopped making them. They are called Coralife Mini Aqualight Compact Fluorescent and they put out 18 watts in a very small space - you could probably fit two on a 12x12.

[fishmommy]

I looked at the hood you are talking about. It has a single screw-type socket that will fit either a 60w incandescent bulb or a screw in CF bulb. I honestly don't know how much light output you will get from that in FootCandles. Hopefully someone else has some experience with that type of bulb.

[Paul Mc]

Well, the three orchids I have thus far that I will be putting in there range in their needs. The highest needs around 1500 fc's, while the lowest is in the range of 500 to 700 fc's. I plan to compensate for this by building more "sheltered" places for the lower light plants and put the higher need plants up closer to the top.

My concern is that my terrarium is only 12x12x18, and I want to be sure that the hood I buy can accomodate various types of bulbs should I need to step up or down the light levels by using a different type of bulb.

I just don't want to buy a hood from a company and then be stuck using only what they offer for that hood which tends to not be very flexible in terms of fc's.

[fishmommy]

tough question - I've reached the limit of my knowledge
good luck!

[Ray]

Aquarium lighting is not appropriate for orchids. T5 or CFLs would be a better choice, but you'll probably be stuck with CFLs, as the smallest standard T5 is 2' long in its fixture.

A single 45W CFL bulb (actual wattage, not "equivalent to") will probably do the trick, giving you the 1500 fc at 6"-9" above the leaves in the middle, dropping as you move to the ends.

[Paul Mc]

Thank you Ray, as always!

I am assuming I can find the appropriate 45w CFL bulb at the local home depot, along with a lighting fixture. Is that correct?

[fishmommy]

T5 and CF *is* what I was recommending in my post. The fixtures for aquariums I'm talking about use those bulbs and are sized for these small enclosures.
Of course, always use bulbs in these fixtures that are the appropriate spectrum for plants, as standard 'Aquarium' bulbs are not appropriate color spectrum.
Sorry if there was some confusion over what I said.

The fixutre I linked is in fact a T5 that is 11 inches, which would fit. I have 6 terrariums that use these fixtures to great effect.

[Paul Mc]

Ray, I looked around and finally found a 45w CFL bulb, not equivalent, and it was HUGE! Is this the right kind of bulb? I was thinking it would be smaller. If I'm remembering correctly, it said it would put out somewhere around 6000 lumens or more.

The 45w equivalents said they would put out about 2800 lumens. As the tank is only a foot and a half deep, do I really need the 6000 plus lumens?

Where would you suggest I look for the bulbs and light fixtures if that was not it?

Sorry for the 20 questions.

[Ray]

A CFL typically puts out about 75 lumens per watt, while a T5 is more like 90. I based my recommendation on some experimenting I did:

A single HO 24W T5 (2160 lumens) with a good reflector gave me a measured light level of about 800 foot candles at 6" distance.

If a CFL is 70 lumens per watt, then a 45W bulb will put out about 3150 lumens (not 6000), which - assuming it had a good reflector - would give you about 1200 fc at 6".

FWIW, when I built my terrarium, I used 3 x 24W T5's, and the light intensity was so great, I had to build the hood so it raised the lights an additional 12" above the tank to avoid burning the plants.