good T5 bulbs that provide spikes in the proper spectrum

[xyyz]

i've read lots about looking for lighting that's between a certain K range; and i started thinking, is this an accurate way to determine the worth of a particular fluorescent bulb?

unlike natural right, if i'm not mistaken, flourescent lighthing doesn't emitt light in all parts of the spectrum. i thought the phosphors used in the bulb determines the part of the spectrum that's emitted. just because something is in the 3k, 6k, 10k, or whatever K rating, it doesn't mean it'll peak in the 400-520nm and 610-720nm ranges. it's quite possible that there won't be much emitted in that these useful ranges right?

is there any list out there that gives a run down, not on the K rating, but on the exact parts of the spectrum these fluorescent bulbs?

also, is there a list somewhere that rates the effectiveness of various fluorescent bulbs commonly available?

 

[fort384]

I know that currentUSA bulbs give a wavelength breakdown as well as the color temp.

 

[xyyz]

like today. i was looking at the hagen power-glo vs. the life-glo. the pg is 18000k while the lg is 6700k. earlier someone told me anything around 18000k was too blue and not effective for plants, but looking at the spectral diagram for both blubs shows the pg has much higher spikes in the light ranges that plants need for photosynthisis.

therefore, again, this business about getting bulbs with certain k ranges seems pretty inaccurate in getting good light for plants.

 

[Purrbox]

The Kelvin rating just indicates the way the bulb color will appear to the human eye and has nothing to do with how the light appears to the plants. The reason that a certain Kelvin rating range is suggested for plants, is that as a general rule the bulbs in these ranges will both appear good to our eyes and tend to provide the light needed by the plants. As you've already discovered this doesn't provide a way to determine which bulbs will be best for the plants, and for that you need the spectral analysis. To get that sort of information you usually need to contact the manufacturers. I know that there are many of the GE bulbs that are particularly good, however this is based on information that is several years old and I don't remember where it was posted.

 

[SpeedEuphoria]

Check out ReefGeek they have spectral graphs for most of the bulbs they sell.

By far the Gieseman Midday and aquaflora are considered the best FW bulbs

 

[Darksome]

So of these four:
Aqua Glo
Sun Glo
and Power Glo
Flora Sun

Which one is best for planted tanks? (Given that they have the right spectrum)

I have a ten gallon and am about to replace my bulb...it is somewhat planted and want the best out of a bulb, preferably one that would encourage growth and pearling.

 

[Purrbox]

Go to your local hardware store, save some cash, and get a bulb in the 5000K - 10000K range. It'll be just as good (if not better) than those "aquarium" bulbs.

 

[Darksome]

Actually in my area it will cost about the same...the aquarium bulbs I can find for cheaper.