floursecant light experts: compact flourescant versus regular flouescant

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dilettante84

AC Members
Nov 1, 2005
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I have found some suggestions that compact flourescants lights put out more light at the same wattage than regular flourescant tubes. I have scoured the net trying to find a comparison of say, a 65w CF tubes light output compared to 65 watts of regular flourescant lighting, or even just the Lumens per watt ratings of typical CF and regular flouresecant lamps, but havent been very successful.

So if someone can answer my question, it would be appretiated. feel free to get techincal.

-does a 65w watt CF lamp put out more light than say, four 15w standard tubes, or two 25 watt standard tubes and a 15w standard tube?

-what is the typical lumens per watt for a 65w CF lamp compared to a typical standard tube?

-in theory does a single 40w tube put out more light than two 20w tubes?

-if a lamp produces 800 lumens, do two lamps produce 1600 lumens or does the light from both combine and simply spread a lesser amount over a wider area?

If the 2 watts per gallon "rules" was devised in reference to regular flourescenat tubes, does it or does it not hold true for CF tubes?
 
the reflector is key

The thing about PC lights is typically that the reflector is so good, at least when you are looking at the AHSupply retrofits. Some other PC light fixtures have good reflectors, some do not, AHS has the best reflectors.

I can compare a dual flourescent to a PC of similar watts, you get better coverage from the 2 bulbs compared to the one, just from the geometry, but the light is more intense form the PC, again due to the reflector.

If you get a light that has no special reflector, you lose a lot of light multiplication the reflector gives. Most dual or triple flourescents have no reflector at all, just white backing, square, not angled. You lose a lot of light poential there.

IMO, lumens is not as important as total wattage, coverage of the surface of the tank (from geometry and reflectors), and light spectrum/ actual color in use.

FWIW, I really like the GE Plant and Aquarium normal output flourescents and the GE Fresh and Salt 9325K bulbs in PC or in normal output flourescents.
 
I have also scoured the internet and other resources for information on the efficacy (lumens per watt) for compact fluorescent lamps, and have not found any actual numbers. Looking at different flourescent technologies, however, (T8, T5, T5HO), efficacies seem to run from about 88 lm/W to 105 lm/W, so there's not a drastic difference between them, and I expect that holds true for compacts.

Lumens is just a measure of light power.

Question 1: If the total electircal power (Watts) of the standard tubes are the same as the total electrical power ofthe CF tubes, according to claims, the CF will put out more light power (lumens), but I suspect the difference is not earth-shattering.

Question 2: I wish I knew for sure.

Question 3: For the same technology, two 20W bulbs should put out nearly the same identical light power as one 40W bulb.


Question 4: Two 800 lumen bulbs put out a total of 1600 lumens. What you do with those lumens is a function of reflectors, distance, and the area over which the light is spread. You can take 10,000 lumens and spread it over an entire room, but the light will be weak, or concentrate it in a tiny beam and cut steel.

Question 5: Provided the 2W/gallon rule was devised for older fluorescent lights (T8, T12, etc.) it should still be pretty good for CF, as I suspect the efficacy isn't that much better, and the guideline is just an inexact rule of thumb anyway.

Now there is a big efficacy difference between fluorescents approaching 100 lm/W and incandenscents and HID's of 15-20 lm/W.
 
so compact flourescent gets much of of improved output from the reflector design. I am not interested in foing the ah supply route, nor can i afford a dual strip fixture right now. does anyone know which of these have the best reflector?

http://www.bigalsonline.ca/catalog/product.xml?product_id=33942;category_id=1875;pcid1=1843;pcid2=

http://www.bigalsonline.ca/catalog/product.xml?product_id=31566;category_id=1875;pcid1=1843;pcid2=

http://www.bigalsonline.ca/catalog/product.xml?product_id=29601;category_id=1875;pcid1=1843;pcid2=
 
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Here is a good description of how re-strike can affect lighting over an aquarium: http://www.ahsupply.com/36-55w.htm

I know you say you have no interest in AH Supply, but when you compare prices for their product vs. the products you are looking at on Big Al's, I would think it would at least be something to consider.
I can't tell from the pictures what the reflectors are like in the Big Al's pictures, but I can almost guarantee you that they are flat polished aluminum at best. The numbers on the page I link to above are not made up or exaggerations. There is a huge difference in efficiency between faceted reflectors and flat ones.
I would suggest that since this is probably going to be your largest monetary outlay for your aquarium, that you get the best available product. IMO, you won't regret it.

Len
 
i dont want to mess with building anything. with ah supply i will end up spending around the same amount when i factor in the cost of buying the pre made canopy thing etc.

Maybe I should make this more simple. Is a single 65w compact flourescant "coralife" enough to grow plants well in a 29g?
 
Pet Supply Liquidators

I got a custom made light fixture from PetSupplyLiquidtors.com, you might want to look at that. I got a Solar Light, just like the 48" one but built only 45" long for an odd sized tank. It is placed over a glass top. I love it, sleek and lightweight, dual switches and dual fans.
 
dilettante84 said:
Maybe I should make this more simple. Is a single 65w compact flourescant "coralife" enough to grow plants well in a 29g?
Click to expand...

Yes. That will put you in the low-light category in which there are plenty of plants that will grow just fine.
 
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