My first REAL DIY project (pics)

[Sumpin'fishy]

Steve is right. Those would be 19 watt bulbs effectively.....so you are now a little over 1w/gal. The "19 watt replaces 75 watts is replacing the effect of a 75 watt incandescent light. These have much less effect on planted tanks, from what I've read. I have also asked around about this issue myself and was told unanimously that you would have 19 watt CF bulbs.

Remember that the 3w/gal rule is subject to change under different circumstances (water depth, clarity, spectrum, etc.), so I would think that since your 19 watt bulb is grouped more tightly than a 15w NO Flourescent bulb, that it is more effective over the area it is over. For instance it probably is brighter for the 6 inch radius under it than a longer NO bulb. The whole advantage of CF bulbs is fitting more light into more "compact" spaces. Yours is even more compact than most CF bulbs sold for aquarium use, therefore MY THEORY is that it is more efficient for the area it covers. I believe that even though you have maybe 1.25w/gal working for you in your tank now, that to add one more bulb would probably get you to the effectiveness of 3w/gal of normal bulbs. This is MY THEORY ...... make your own assumptions!

There are so many variable in these "formulas" that I'm learning to find a "starting place" and work from there with personal experience. I'd suggest the same to others

 

[morleyz]

Ok...but here's my question: I have a 15W standard flourescent fixture. I have my DIY fixture which you're saying is effectively 19W (with one bulb on). The DIY fixture is MUCH MUCH MUCH brighter than my 15W.

EDIT: Here's some more info:

http://www.misty.com/~don/cf.html

A quick synopsis:
"Many light output claims are outright exaggerated, often by about 15 percent and in few extreme cases by 25 percent."

From what I gather, the light output is not what is advertised (which is what I thought) but it is still significantly higher than the wattage drawn..75% of a 75W bulb is still 56W...so by that measure I'm looking at 112W of output.

 

[Sumpin'fishy]

I hear what you are saying, and that's where I get my offshoot theory. I don't believe they are exactly the same as a NO 19 watt bulb (even if they made one), but I have done tons of research on this topic and none of them say that CF lights are more efficient....they all pretty much go watt for watt (with the variables I mentioned before taken into account).

Here are a few of the sites I looked at:

http://www.thekrib.com/Lights/

http://www.aquabotanic.com/lightcompare.htm

http://www.fullspectrumsolutions.com/Fluorescent.htm

http://www.whatwatt.com/default.asp

Anyways, those and many others are where I've done reasearch on lamps and their effects.

HTH
Mark

 

[Skippy]

See,

The fullspectrumsolutions one there lists a CF "replacement bulb" which puts out 55 watts of CF lights. With that I'd only need about 6 bulbs to hit my goal of around 3wpg.

Many of the others though just say 19 or 23 watts which really isnt what i can use.

ALso, the fullspectrumsolutions ones show a 6500 color temp on them. I see they have "spot light" hoods for thier smaller bulbs, I wonder if anything like that could be constructed for these larger ones.