For a setup like that there are specialized concerns like heat build up, maintaining humidity etc. I would suggest asking this question on the terrarium forum here as there would be many folks who are doing what you wish to do who could advise you.

I'm looking into the same issue myself. From what I gather so far, there are three realistic options for a sealed tank.

A: T5(5/8") fluorescents(high output, vho also, but they require even more expensive ballasts/starting units than the standard t5s which are expensive as they are)

B: Compact fluorescents, these do give off a bit more heat, but I think they still may be suitable, an example of these are envirolites or just your average 55w cfl that you can pick up in a shop. You'd have to make sure to get one with an integrated ballast, unless you can actually find a separate ballast.

C: T8(8/8") tubes(avoid the supers, they require an expensive ballast), again need separate ballasts(electronic is generally better than the old magnetic coil driven starters) which are around $15-20, tubes vary in price but from what I've seen, triphosphors don't look like much use, sylvanias gro lux or interpets beauty light are pretty reasonable for growing plants.

I'm thinking t8s are probably the best option as they don't have to be replaced too often, can be overdriven, don't put out too much heat, and are reasonably priced.

However, I've only been looking into this for a short period of time, may be wrong.

RP1

Ok... heh heh, whats a ballast?

Basically the starter for fluorescent lighting.

RP1

Lightmaster to the rescue!

A: T5(5/8") fluorescents(high output, vho also, but they require even more expensive ballasts/starting units than the standard t5s which are expensive as they are)

T5 lamps can run off the standard T8 ballast without harming the lamp or the ballast. Plus you can overdrive them.

C: T8(8/8") tubes(avoid the supers, they require an expensive ballast), again need separate ballasts(electronic is generally better than the old magnetic coil driven starters) which are around $15-20, tubes vary in price but from what I've seen, triphosphors don't look like much use, sylvanias gro lux or interpets beauty light are pretty reasonable for growing plants.

again...you don't need supers when you can make your own by overdriving them. At my HomeDepot, there are 4tube T8 ballasts for 17.94 and I can Overdrive them into a 2tube fixture.

Not very many magnetic ballasts can run T8's
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tfraleigh said:
Ok... heh heh, whats a ballast?
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A ballast is a transformer that is needed to keep the fluorescent tubes from blowing up. At startup, it creates a really high voltage to start the lamps, and a low voltage to keep them running. When you look inside the fixture, generally the ballast is black and is about 6 to 9 inches long with lots of wires going to the sides of the fixture.

T8's are the best option because they are easier and cheaper to find.

-j-

Ok ok, my bad as to a:. Getting confused by bloody interpets non standard compact t5s which have their own starter units.

Cheers for the info lightmaster.

RP1

Forgot to mention, this is also thoroughly confusing:

http://www.aquatics-online.co.uk/Z044147.asp

Check out the hagen glomats, "apparently" electronic ballasts, for t8s only.

RP1

Rising Power, your primary consideration should be efficiency, that is how much light from how much electricity. The initial cost of the fittings and the ballasts will be swamped by the cost of the electricity before you ever change a bulb. On the same lines, consider how long the bulbs will last and how much dimmer they will get as they age. Compact fluorescents are generally less efficient than the best straight tubes (although better than older designs), so don't use them unless you need a simple setup for occasional use or need to light a compact space where long tubes won't fit.

Nothing wrong with triphosphors, the most efficienct fluorescent will likely be a triphosphor and the spectrum is OK. Be very sure what you are doing before you dismiss them and don't fall for any "wide spectrum daylight" marketing bull selling you an overpriced underpowered tube. Think about whether your plants need a particular spectrum and whether you need a particular colour (or colour quality) bulb to enjoy the view.

Well that said, envirolites are putting out around 12500 lumens per bulb @ 125w, being the only cfls I'm looking at.

I dismissed the polylux from ge based upon the spd's for it, which only showed a slight rise in both the blue and red, and a large peak in the green. I'm not sure they were any better than a normal halophosphate except in terms of life.

I'd have a look at the lumilux from osram, if the only option wasn't to buy it in bulk, albeit cheaply. I'd end up with 25 of warm white or daylight, not a mix.

Sylvania don't seem to have any reasonable triphosphors, so that doesn't leave much.

RP1

Hm, so now that this conversation has gotten into the deep details of lights and completley left me in the dark (gettit? ha ha, not.) could somenone tell me what i should be looking for in lights that would be growing my Orchids? Spectrum, color range, im sorry, bu im colpletyly lost in thie stuff. Do they need to be special UV lights like reptiles need?
Sorry about all the probably newb. questions, but anyone who helps me out would be top in my books.
Thx kids.

Plants only use light in the blue and red parts of the spectrum, I think two important peaks are around 420nm and 670nm. So having UV light would be pointless to them.

The question I'm not sure about is how much the output of the tubes matters, vs the spectrum they output at each level.

http://www.aquabotanic.com/images/light_fig9.jpg is the output you're ideally looking for from lighting, but it generally doesn't come that close, except in the case of the sylvania gro lux, maybe a few others.

RP1

Just said something a little stupid, they also use light in the green part of the spectrum too but it's generally not as relevant as the blue and red parts of the spectrum.

RP1

So what should i look for on a light that i would consider for the tank?

could somenone tell me what i should be looking for in lights that would be growing my Orchids?

Unfortunately this isn't possible. Orchids are a diverse group of plants and their lighting requirements vary from high to low light plants. A clue to lighting requirements is finding out where your orchids grow naturally. Some grow in full sun in the tropics, others grow under forest canopies. Color spectrum isn't terribly important as long as you have the red and blue spectrum covered(this is very generic advice and applies to most anything grown under artifical lights).

I highly recommend visiting the orchid lady's site for more info. She has a contact email on her site and will respond to questions. She also has 'indicator' signs that an orchid is getting not enough, the right amount or too much light.

Everyone says compact flourescents are cheaper than the tube lights, but the one's ive come across that are advertised for growing are kinda more pricey than the tube ones. Does haveing an internal ballast make them more pricey?

I was looking at this light fixture (sp?) for the top, I'd use two CF's and one reptile tube UV light for my frogs, would this work?

Here is a link that might be useful: Combination Hood

Well I'm now looking at wiring up 2 t5 ballasts for some t5ho tubes. CFLs have the disadvantage of having to be replaced pretty often, the t5hos last and last and probably give out a lot more light(17800 lumens for 4, maybe more).

Of course you could use t8's, maybe overdrive them. You're spoilt for choice in the US. Maybe take a look at some t8 lumilux daylights and internas/warm whites.

I think cfls are worth it if you can buy them in bulk cheaply, otherwise, you'll find costs mount up.

RP1

The only reason a compact fluorescent is cheaper is that there is no setup cost for fittings and ballasts, you just plug them into a standard outlet. They are less efficient, mostly don't last as long as a fluorescent tube, and cost more to replace, so for extended use they are more expensive. Use them either for occasional use such as seed starting where compact size and low setup costs are useful, or when you don't have the room for long tubes and don't want to move to HID lamps.

BTW, the cost of the bulb itself is almost irrelevant when you calculate cost over the full life of the bulb. Electricity is the biggest cost. If CFL bulbs were free, 40W (or so) fluorescent tubes would still be more cost-effective over the several thousand hour lifetime.

I personally don't see CFL bulbs as being less efficient per wat than regular tube lights. They also last a fair amount longer in my experience as well. I use larger CFL lights at 85W, but the difference in light output from when I used 2 2 bulb fixtures is nothing short of amazing.

So I'm using about 10W more and getting loads of additional light and my plants and I couldn't be any more pleased.

D.

85W CFL output is around 5,500 lumens, that's about 65 lumens/W and is typical for all CFLs.

A high output T5 or T8 tube will put out around 90-100 lumens/W, the equivalent of about 8,000 lumens if there was such a thing as an 85W tube.

Seems like a big difference to me. I suspect you are mistaking the high intensity of the CFL output from a small area with the greater total light output from straight tubes over four feet long.

Last longer? The quoted life for the 85W CFLs is 10,000 hours. I've seen CFLs up to 15,000 hours although not in the higher powers. F54T5 tubes are typically rated for 20,000 hours plus better lumen depreciation. 20,000 hours with better than 90% lumen depreciation is considered a minimum for a modern T8 tube. Lamp life up to 30,000 hours is not uncommon; the startup is sometimes slower but this is not an issue for a plant light.