# Difference between flourescent,T5,T8,T12 lighting



## ShrimpieLove

Hi everyone! 
Just looking at lighting stuff today, i like my lights for now but im wondering whats the difference between the flourescent tube lights, and T5, T8, T12 etc...? If i upgrade it will probably be one of those choices but I dont know what is better about a T5 or T8 from just a regular aquarium flourescent tube... I can see all the types online at big als but they dont explain the differences between them ?


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## bae

The T number is the diameter of the tube in tenths of an inch.

Which tubes you can use depends on your ballast. Most ballasts can drive only one wattage of tube, although ones that will drive both 32w T8 and 40w T12 are still common. In general, the length of the tube is directly proportional to the wattage for a given T number for T8 and T12. I don't have any experience with the newer T5 tubes.

Usually, there's an F number as well as a T number printed on the tube. The F is the wattage. F40T12 and F32T8 are the most common (and therefore cheapest) tubes. They are both four feet long. F20T12 is the common two foot long tube. Ballasts usually have paper stickers saying which (and how many) tubes they can drive.

T8 and T5 emit more light for the same wattage than T12. You can buy standard T12 and T8 tubes as well as a number of other kinds at any hardware or building supply store, a lot cheaper than at an aquarium store. I like 'cool whites', but there are also 'daylight' and 'sunlight' types which work well to grow plants. Pick one that looks good to you.


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## Darkblade48

bae said:


> The T number is the diameter of the tube in *tenths *of an inch.


The number after the T indicates the diameter of the tube in *eighths* of an inch.


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## Chris S

To put it simply, a T-5 bulb is just more efficient than a T-8 or T12.

A T-5 HO is a T-5 size bulb, with the ability to produce more lumens (ie. uses more wattage).

For instance, a four foot T-5 bulb uses 24 watts (I believe...) while the same size T-5HO bulb uses 54 watts.

Compare these to a four foot T-12 for example, which uses 40 watts but produces less usable light than a normal T-5. A T-5 HO uses slightly more wattage (+14 watts), but produces almost double the amount of lumens of a T-12.


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## bae

Darkblade48 said:


> The number after the T indicates the diameter of the tube in *eighths* of an inch.


Oops. Right. Thanks for the correction. I shouldn't post before I've had my second cup of coffee!


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## KhuliLoachFan

"t5 high output (ho)" is the usual choice for planted-tank enthusiasts and low-end marine users. The high end marine users (and some planted tank afficionados with lots of cash) go all the way up to metal halide.


W


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## Chris S

I would say that T5 HO is a better choice for marine as well.


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## igor.kanshyn

Once I saw a 2' fixtures in HomeDepo. They holds two T5 14W bulbs.

The question is can I buy this fuxture, through away those bulbs and replace them with more powerful ones (24W Surface-Water T-5 Bulb - 24", for instance)? Will this more powerful bulbs work in that fixture with existing ballast?


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## Chris S

You have the check the ballast, but I would imagine it will only support a 14w bulb.


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## KhuliLoachFan

The ones at home depot will take a T5 but won't support T5 HO.

Also you'll need a proper reflector.

There's some hydroponics place near Burlington that supposedly has really good prices on T5 HOs. I guess people use them to grow their..... herbs.... you know?


W


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## igor.kanshyn

You right about reflector. Those fixtures from HomeDepot cover bulbs only from the top.


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## ShrimpieLove

I have a planted tank so I suppose a T5 or T6ho would be good for Me...
one more question... is 6700K or 10000k better for planted tanks? I saw a T5 with 6700k tube plus a Roseate tube(not sure what that one does) that said its good for planted tanks.. but I wondered if 10000k is better for planted tank or not.. and what a roseate bulb does?


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## igor.kanshyn

T6 is an old standard. Don't buy them.

Plants don't carry a lot about color temperature, but you will do 
10000K makes everything blue like in SW aquariums. Even 7000K make aquarium not so good looking.
With 6400-6700K light your tank will look better, plants will be greener, fishes more colorful. 

Those Roseate (they are usually called Pink) bulbs have color temperature 5000-5500K. They have more reddish color, like sunrise or sunset. 
There are some light fixtures on the market where 10000K or 12000K bulbs are mixed with ping bulbs. In a result you will have something similar to 6700K


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## ShrimpieLove

ahh ok so a 6700k would be best, thanks


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## BillD

Most 6500K tubes have a lower CRI (Colour Rendition Index) than 5000K tubes, so, you would get much better colour rendition with the 5000K. An example would be Philips Natural Sunshine. Daylight tubes (6500K) are not really "daylight". Plants will grow well under them, but it is a bluer light and some colours don't show up well under them. Still, lots of people like them. 
I grow plants well enough under T8s which is the new sweet spot in terms of economical tube pricing, as it is the new standard. Appropriate tubes are easy to find in T8; less in the T5.


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## Russgro

Here is an article from "BlueRam" and "Shalu" over on the planted tank forum. 
http://www.plantedtank.net/forums/lighting/21052-comparison-lighting-types-lumens-watts.html


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## Zebrapl3co

Russgro said:


> Here is an article from "BlueRam" and "Shalu" over on the planted tank forum.
> http://www.plantedtank.net/forums/lighting/21052-comparison-lighting-types-lumens-watts.html


Nice link. But unless I am interpreting it wrong. I don't agree with the chart though. LED is much more effective that most of the lights out there and yet, in this chart it might as well be consider garbage.
Also, how can a T12 HO or VHO be even worst that a normal T12?

And another thing, it just depends when it comes to how deep is your tank. T5 HO can penetrate deeper in to the tank allowing it to reach carpet plants while T12 have a limited dept.

I just don't get it ....

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## igor.kanshyn

Zebrapl3co said:


> Nice link. But unless I am interpreting it wrong. I don't agree with the chart though. LED is much more effective that most of the lights out there and yet, in this chart it might as well be consider garbage.


If they are referencing on stuff like this one, they are right.


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## Russgro

This chart is based off watts over lumens, its math, its not an opinion. Its just giving efficiencies of the bulb its self, nothing to do with reflectors. So you may think that because of the LED systems you've seen are real bright this is just comparing bulbs.


quote from article "This article does not address issues such as how much light you need for a given tank or what spectrum means"


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## Zebrapl3co

igor.kanshyn said:


> If they are referencing on stuff like this one, they are right.


Actually, that looks pretty good for the price. And it's chewing only ~ 13 watts. Didn't say what the lumens are ...



Russgro said:


> This chart is based off watts over lumens, its math, its not an opinion. Its just giving efficiencies of the bulb its self, nothing to do with reflectors. So you may think that because of the LED systems you've seen are real bright this is just comparing bulbs.
> 
> quote from article "This article does not address issues such as how much light you need for a given tank or what spectrum means"


That's my point. I am questioning the numbers.
So I did a bit of googling.
Here's one that seems more reasonable:








http://ecmweb.com/ops/electric_fluorescent_lamp_coming/
Don't get me wrong. The orginal post is still an eye openner for me. It's just that I find the numbers to be too far apart ....
I can't seem to find any good info on the LED ...
Edit:
OK, here is another one that is less trusable but still it gives a bit of how big a gap it is:
http://members.misty.com/don/lede.html


> *Where some of those really impressive lumen per watt figures for LEDs come from!*
> 
> I remember seeing "luminous efficacy" in LED datasheets, with really impressive numbers. And these numbers were always high, even back around 1980. Yellowish green LEDs always had numbers around 600 lumens per watt for this. The catch is that this is the luminous efficacy of the emitted light, a characteristic of the emitted light used for converting between radiometric units (watts) and photometric units (lumens). Divide the millicandela by this figure to get milliwatts per steradian. Divide the mW/steradian by the square of the distance (from the LED) in meters to get milliwatts per square meter.
> 
> Any wavelength of visible light has a characteristic lumen/watt luminous efficacy figure. This is approx. 683 lumens/watt times the Photopic Function of that wavelength. Light having more than one wavelength would have a luminous efficacy which is an average of those of all wavelengths present, with weighting for the amount of light present at each wavelength.
> "White LED light" has typically roughly rough-ballpark 300 (often a little less) lumens per radiated watt, with one recently announced especially efficient prototype having 331 lumens per radiated watt (and "only" 91.7 lumens per input watt, meaning 27.7% efficiency of converting electricity to light). A more recent still laboratory prototype white LED (announced 12/22/2006) achieving 150 lumens out per watt in probably has slightly higher lumens out per watt in by having a more favorable more yellowish shade of white (but more "pure white" than yellowish, 4600 Kelvin color temperature) than most white LEDs including the 91.7 lm/W one, so I guesstimate 350 lumens out per watt out, so 150 lumens out per watt in is about 43% efficiency of converting electrical energy to light. Bottom line: LEDs with datasheets claiming 150-600 lumens per watt are specifying lumens per watt of light output, not lumens per watt of electrical input.


This means that the input lm/W may have been 91.7 but the outpout can potentially hit 150 - 600 lm/W depending on the wavelenght (K rating?)

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## Zebrapl3co

Here is another one, it's getting pretty confusing as every graph seems to have their own opinion:








http://electronicdesign.com/article...r-led-lights-the-way-with-a-160-lumen-ou.aspx

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## Harry Muscle

Zebrapl3co said:


> Nice link. But unless I am interpreting it wrong. I don't agree with the chart though. LED is much more effective that most of the lights out there and yet, in this chart it might as well be consider garbage.
> Also, how can a T12 HO or VHO be even worst that a normal T12?
> 
> And another thing, it just depends when it comes to how deep is your tank. T5 HO can penetrate deeper in to the tank allowing it to reach carpet plants while T12 have a limited dept.
> 
> I just don't get it ....


LEDs are actually not as efficient as most people assume. They have only become more efficient than fluorescents only a few years ago and those are the pricier ones. The average LED is actually less efficient than a lot of other types of lighting.

Now where the confusion comes from is that usually we want lighting in one place, in our case the fish tank. A flourescent bulb shines in every direction and we need to use reflectors to point it into the tank, all of this bouncing around looses light and decreases the amount we actually get in the tank, but it doesn't decrease the actual light output of the bulb (from a manufacturers point of view). An LED by design only produces light in one direction (in a cone actually), so there's no reflectors required, no bouncing light, etc, it's straight from LED to the subject. However, from a pure wattage input = lumen output, LEDs are not that efficient. And that's what that graph describes.

Harry


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## Zebrapl3co

Harry Muscle said:


> LEDs are actually not as efficient as most people assume. They have only become more efficient than fluorescents only a few years ago and those are the pricier ones. The average LED is actually less efficient than a lot of other types of lighting.
> 
> Now where the confusion comes from is that usually we want lighting in one place, in our case the fish tank. A flourescent bulb shines in every direction and we need to use reflectors to point it into the tank, all of this bouncing around looses light and decreases the amount we actually get in the tank, but it doesn't decrease the actual light output of the bulb (from a manufacturers point of view). An LED by design only produces light in one direction (in a cone actually), so there's no reflectors required, no bouncing light, etc, it's straight from LED to the subject. However, from a pure wattage input = lumen output, LEDs are not that efficient. And that's what that graph describes.
> 
> Harry


Yes, I think I know which one you are talking about. It's this one:
http://www.luxeonstar.com/Cool-White-6500K-20mm-Tri-Star-Rebel-180-lm-p/mr-wc100-20t.htm
The price is as expensive as ever. Some things never change.

Here is a more compreshensive chart from Wikipedia:
http://en.wikipedia.org/wiki/Luminous_efficacy
This one makes a lot more sense as it is propertly researched and have reference sources. Sorry, LED is much more efficient than flourescent.

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## Harry Muscle

Zebrapl3co said:


> Yes, I think I know which one you are talking about. It's this one:
> http://www.luxeonstar.com/Cool-White-6500K-20mm-Tri-Star-Rebel-180-lm-p/mr-wc100-20t.htm
> The price is as expensive as ever. Some things never change.
> 
> Here is a more compreshensive chart from Wikipedia:
> http://en.wikipedia.org/wiki/Luminous_efficacy
> This one makes a lot more sense as it is propertly researched and have reference sources. Sorry, LED is much more efficient than flourescent.


LEDs "can" be more efficient (and only in the last few years), but that doesn't automatically mean that they are, just make sure you do your homework when choosing an LED and don't automatically assume they are more efficient ... then again once you factor in the reflectors you have a good chance they are more efficient at getting light into your tank even if they might not be as efficient at producing the actual light.

Harry


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## Zebrapl3co

Harry Muscle said:


> LEDs "can" be more efficient (and only in the last few years), but that doesn't automatically mean that they are, just make sure you do your homework when choosing an LED and don't automatically assume they are more efficient ... then again once you factor in the reflectors you have a good chance they are more efficient at getting light into your tank even if they might not be as efficient at producing the actual light.
> 
> Harry


OK, I see what you mean now. You are right, you do need to buy the correct types of LED. The ones with high candela are the ones you should be looking for.

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