Comparison of Lighting Types (Lumens and Watts)
Comparison of lighting for PlantedTank.net
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 Olsens 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
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)
* 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.
Operation described here: Diagram of a Light Bulb
Aquarium 15 W bulb ~7.4 lm/W.
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
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.
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!
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?
The above post is designed to directly compare lamp types in terms of Lumen and Watts. Response to: http://www.plantedtank.net/forums/sh...ad.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:
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.
Ok, I swapped my Advance REL-4P32-SC out for a workhorse 8.
So the advance is spec at 0.94A for 4 X 4' T8 or 235mA.
The rated current of a 4' T8 is 265.
so 235/265 88% power factor!!!
Now the WH quotes PF > .90.
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?
I love wikipedia.com
Lumens doesn't tell much how good a bulb is growing plants because lumens is weighted towards human response (our eyes are sensitive to yellow-green, the same light plants *reflect*):
so does this mean we only go for what has the best K rating? what is the best K rating forour plants?
we have found an 18Watt philip Flousresecent light with 6200K rating. would that be good enough?
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.
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.
So if I got four of these bulbs..http://www.lightbulbsdirect.com/page...2-D-HO....over a 100 gallon tank equaling up to about 2.2 watts per gallon...would that be ok for a low to medium lighted planted tank??
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.....
Good research and info, have you done any research into the T8 tri/quad/penta phosphor tubes?
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.
I agree Newt. PUR-efficiency is a better way of comparing how much photosynthetic "power" you get for the electricity bill.
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
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