The Planted Tank Forum banner

Comparison of Lighting Types (Lumens and Watts)

110K views 44 replies 26 participants last post by  alinam973 
#1 · (Edited)
Comparison of lighting for PlantedTank.net

Preamble:
• This article is designed to compare several popular lighting types in terms of power (Watts) and light (Lumens) only. Issues such as spectrum and lighting selection will not be addressed.
• Link to WPG: Lighting: the WPG rule
• Eric Olsen’s comparison: Lighting Level for Aquatic Plants
• Energy/area method: foot-candles, lux, lumens, sunlight, PAR
• DIY (do it yourself) projects have an inherent risk above standard operation. Any DIY ideas mentioned here are for completeness only and does not constitute and endorsement. Water and electricity do not mix!
• Guides the PAR/PUR alternative for can be found at light compareand DefBlog - PUR-efficiency list


Nomenclature

• Total intensity is expressed as lumens (lm).
• Power as Watts (W).
• Power levels: Normal Output (NO), High Output (HO), Very High Output (VHO), and Over-Driven Normal Output (ODNO)

Summary Table:

* Quote: Buy Tools, Lighting, Electrical and DataComm Supplies at GoodMart.com unless noted
# fluorescent bulbs = 4‘,
## (high, - (quoted) - low), lm/W from mean value
### multiplier of intensity to compare T12. Ie 28W T5 = 1.37 W T-12.
Example 2 WPG T5 = 2.74 WPG T12.
+4hydroponics.com

Incandescent bulbs
• Operation described here: Diagram of a Light Bulb
• “Aquarium” 15 W bulb ~7.4 lm/W.
• Color ~2850K

Linear fluorescent lamps
• Operation described here: How do Fluorescent Lamps work?
• Bulb diameter: T-12 -> 12 one-eighths or 1.5”. (T8 = 1”)
• Medium bipin contacts used for T12 NO, T10, T8 and T6 in standard lengths.
• From ~3000K to 6700K

High Output
• T12 High Output variants: The HO and VHO T12 lamp use recessed double contact to prevent interchange and operate by increasing the current (T12 NO = 430 mA, HO = 800 mA, VHO = 1500 mA)
• T5 High Output variants: The T5 and T5 HO use the same miniature bipin contact but require a load sensing ballast.

Under/Overdriving
• Ballast power factor is the ratio of the lamp design current over the supplied ballast current.
• For example a energy saving T12 ballasts can have 0.88 power factor resulting in 2775 lumens X 0.88 = 2376.
• Fluorescent lamps can be “overdriven” with a high power factor ballast, or creative wiring. Over-Driven Normal Output ODNO is covered in depth here: www.plantedtank.net/odno.html
• Rule of thumb is 2X = 50%, 3X = 75% lm, 4X = 100% increase.
• The member “Shalu” notes that some combinations actually become more efficient when OD. Suggested that 2x OD 18" T8 outputs 2.5x light!

Other lamps:
• Spiral Compact as screw in type. Total lm quoted, expect significant loss to restrike.
• Reports that power compact (PC) are bent T5 with 55/66W power dependent on ballast, not bulb.
• HID operation: How does an HID lamp work?

Contributors:
• “BlueRam”
• “Shalu”
 

Attachments

See less See more
1
#2 ·
The above post is designed to directly compare lamp types in terms of Lumen and Watts. Response to: http://www.plantedtank.net/forums/showthread.php?t=20939

This article does not address issues such as how much light you need for a given tank or what spectrum means. I recommend you visit:
http://www.plantedtank.net/articles.html

Finally, this is a draft. Please post typos and I will attempt to fix. For example the table appears at the bottom and not under "summary table" where it should. Please do not post "corrected" bulb values of less than ~10% difference.

Enjoy!
 
#4 ·
This is a great article! I did have one question though. The caveat it I know very little about lighting, and its measurements. Is this saying that in order to get the same ammount of light from LEDs as 40 watts of T12 I would need 91 watts worth of LEDs? I am having a hard time believing this, as my one watt LED headlamp is enough to blind you. I can't imagine 90 of these.

I guess I am asking more about what is a lumen. Isn't it a measurement of how much light we can see?
 
#9 ·
Should work just fine. Anything between 5000k and 10000k will work. 5000k will be more yellow to the eye and the higher "K" you go the more white/blue it will look.
 
#10 ·
The above article intentionally does not cover color, reflectors, or best bulb to keep the focus on bulb types. The good news is that bulbs are cheap so feel free to try a bunch of combos until the aquarium is most pleasing to you.

teban said:
so does this mean we only go for what has the best K rating? what is the best K rating forour plants?
 
#11 ·
#12 ·
Do most people who use t-12 lighting have the recessed end like it shows in the link above? I havent been able to find and bulbs over 40 watts with the two prongs at the ends like normal fluor. bulbs.....
 
#14 ·
Why discuss lumens for their effectiveness on aquarium plants? Lumens is meaningless for plants. Plants do not utilize green light for photosynthesis. A higher lumen rating at the same wattage often means greener light. Lumen is a rating weighted entirely towards human perception. It has little to do with the value of a light for either growing or viewing plants.

Lux is lumens/square meter, so they are similar. They are both defined in terms that are meaningful to human perception of light – not plants. They stress the amount of energy in the green band to which humans are most sensitive – not plants.

Lumen is a measure of flux, or how much light energy a light source emits (per unit time). The lumen measure does not include all the energy the source emits, but just the energy with wavelengths capable of affecting the human eye. Thus the lumen measure is defined in such a way as to be weighted by the (bright-adapted) human eye spectral sensitivity.

The standard measure that quantifies the energy available for photosynthesis is "Photosynthetic Active Radiation" (aka "Photosynthetic Available Radiation") or PAR. This is blue and red light. This is why it is so important to get the spectral output of a bulb before deciding if is a 'good plant light'. You may need to add/mix bulbs to get a lighting that has good visual effects for the human eye and proper light for plants; because 'plant bulbs' tend to be purplish.
 
#17 ·
Why discuss lumens for their effectiveness on aquarium plants? Lumens is meaningless for plants. Plants do not utilize green light for photosynthesis. A higher lumen rating at the same wattage often means greener light. Lumen is a rating weighted entirely towards human perception. It has little to do with the value of a light for either growing or viewing plants.
Agreed. The utility of comparing Lumens in the context of the above post is that the number is generally printed on the bulb or easy to find. So if the question is how much better is Brand X T12 at Y color from Brand X T8 at Y color and if the assumption that the specturm is close enough holds, we can say that in terms of OUTPUT T5>T8>T12. This is important for the person who thinks a 40W T12 is 25% brighter than a 32 W T8!

Where I get into serious trouble is the comparison of incandescent, fluorescent, and halide technologies. The Lumen number just does not fully capture the output and does not serve as a decent comparison.

I would be more than happy to retest various light combos with a power meter. All I need is the hardware :)
 
#15 ·
I agree Newt. PUR-efficiency is a better way of comparing how much photosynthetic "power" you get for the electricity bill.

The standard measure that quantifies the energy available for photosynthesis is "Photosynthetic Active Radiation" (aka "Photosynthetic Available Radiation") or PAR. This is blue and red light.
PAR is everything between 400-700, so that contains green too.

PUR is PAR too, but weighted towards a general photosynthetic action spectrum - which limits the importance of green and yellow.

Aqua Botanic-light bulb comparison
 
#19 ·
Thanks for the link. I added it to the original article. The Ivo Busko article answers the next logical question as to what PARTICULAR bulb and therefore outside the scope here. Please PM me if you would like to see portions of the original article modified. :)
 
#21 ·
I would like to say thanks on how helpful these posts have been. Question, what would be the effects of using a magnetic ballast with starter with T5HO tubes?
While the bulb may light, the idea behind T5 is to use electronic ballasts to the fullest to maximize output for a given current consumption.

"The T5 lamp is currently designed for operation only on high-frequency, rapid-start, or programmed rapid-start electronic ballasts."

http://www.pnm.com/customers/tech_guides/PA_11.html "How to Make the Best Choice"

A Workhorse or other T5 ballast is rather easy to find. (the endcaps and bulb length are also different)
 
#24 ·
I think it's as useless as the prior post suggest here in this thread.
It does not measure what the plant's are receiving, you need a meter to measure that and to fairly compare light from one tank to another.
It's a good attempt however. But nothing beats measuring the plants and in the tank in question.

This also gets around brand names, reflectors, smugdes on glas,s lids or not, differing plant heights, corners, uneven lighting(bright in some places, not so bright in others) etc.........

PAR meters are relative cost effective and the data is more useful.
You may share or perhaps even rent one from another member etc, then adjust the light to where you want it.

Apogee makes a cheaper version and they are about as good as LiCOR's.
A few clubs bought one to share amongst their membership(not a bad way to go).

I honestly have never had issues with the W/gal rules, but the light has become more efficient so I've gone to lower and lower light watts over the years.

So what was once 2-3 W/gal, might be 1 or 1.5w/gal today.
A meter gets around that issue also.


Regards,
Tom Barr
 
#25 ·
Confused with lighting situation

I have a 20gal tank...not an extra high or long. the hood is an eclipse 2 with 2 bulbs (18inches) that came with the hood T8-15Watts. I changed one bulb to a Plant and Aquarium (by Philips) 15Watt with 410 Lumens with a color temp of 2700K. The other bulb is a Natural Sunshine (by Philips) 15Watt with 590 Lumens and color temp of 5000K and color rending of 92.
My substrate is fluorite. i have anacharis, anubias nana, and a microsword.
Is my lighting sufficient? also if not...where do i find a local retailer that sells a higher wattage bulb.
my other question is when 6500 Kelvin is recommended...is it per bulb or combined?
Thanks for your help
 
#26 ·
Kelvin ratings don't "combine." If you have 2 x 6500k bulbs in there, your lighting is still 6500k, not 13000k. That being said, yes I highly recommend you keep within the range of 6500k to 10,000k. Your 5000k bulb is close so that one may be okay (albeit a little too yellow for my liking), but I think that 2700k one needs to go. That's the spectrum you would use if you were growing fruits and/or flowers in a terrestrial garden.

I don't know much about the Eclipse tanks, much less their hoods, but I do think that 30w will be sufficient in a 20g tank, to be able to grow low light plants anyway. But you should make sure they are in the right spectrum. Pay little-to-no attention to marketing gimmicks that claim certain bulbs to be "for aquariums" or "just like sunlight" or whatever. Just simply go out there and grab some 6500k T8 15w bulbs. I personally tend to like blending 6500k and 10,000k in my tanks. It makes for a very crisp, white light, that is neither too blue or too yellow.

But this is just my opinion of course.
 
#27 ·
ok. Thanks so much! I will change the bulbs from your recommendation. a 6500K and a 10000K bulb. So when i am looking at the watts per gallon. im only pushing 1.5 WPG. will that be enough?
Just for my own enlightenment. If the WPG is not really a concern...and only the K is concerned, what happens with a larger or a deeper tank?
Thanks for your time
 
#29 ·
If the WPG is not really a concern...and only the K is concerned
These are both untrue statements, so don't get confused again. Wattage is still a concern but WPG is not really the best way to look at things. It's just a generic guideline people use for lack of anything better. And saying that only the K is concerned is also very false, because even if you have the correct spectrum, what does it matter if the light doesn't reach the plants because it's too low of a wattage?
 
#28 ·
Kelvin rating only refers to the color of the light coming from the bulb and has little to do with anything other than aesthetics when it comes to a FW planted tank.

I know there's quite a bit of discussion of Actinic light, coral photosynthesis, and water penetration over in the SW hobby, but that's not really applicable to the FW side.
 
#31 ·
I would like to add that the webpage referred to a few posts back is very wrong when LED is concerned. The lumen-requirements stated there are based on non-directional sources. LED is extremely directionally focussed (usually beaming 120 degrees or less). Meaning the lumen reaching an aquarium bottom surface would be much much lower than the requirements stated on that page, yet would be more than enough for plants and the human eye.

With LED there is no loss at the back (top of aquarium) or sides, so you need no reflectors either. It is also noticeable that the light from LED does not reach out of the sides of the tank, as other lighting does.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top