Lighting Number Differences??

[DJM28064212]

I am in the market for a new lighting system and have come across many different numbers. I was wondering if anyone could give me a quick over veiw on the difference between 10,000 Daylight, 6,000 Daylight, 6,500 Daylight, and any other numbers that are common. Thanks

 

[CaptainDave]

the numbers are Kelvin values, I believe, and refer to the color temperature of the bulb. 6,000 and 6,500 are a yellowish color, 10,000 tends to be white or white with a touch of yellow, 14,000 tends to be white with a touch of blue, and 20,000 is blue-white.

The lower Kelvin bulbs generally give you better growth, but not as much coral fluourescence ("pop"), and the higher Kelvin bulbs generally give better color but not as quick growth. Some people step up a wattage size when running 20K bulbs.

every bulb is different, though, and you should investigate the specific bulb you are interested in.

 

[manderx]

and the reason they are called color 'temperatures' is because that is the theoretical color a black-body radiator would be at that temp. get something hot and it glows red, hotter and it glows white, hotter and it glows blue.

with all that said, the numbers the marketing department writes on the bulb isn't as meaningful as they should be. i've seen some bulbs with a 10K label on them that were bluer than one with a 20K label. and to further complicate things, the color and intensity a specific bulb burns at can be vastly different by ballast.

a good place to look at different combinations is here-
http://www.reeflightinginfo.arvixe.com/
go to spectral plots and compare 2 bulbs. you can compare wattage/bulb/ballast combinations. another number that alot of people look at on that site is the PAR (or PPFD). this is the theoretical brightness as plants see it. some debate on how meaningful it really is, but it's probably better than nothing.

this will give you a good starting point in picking bulbs, but really the best thing to do is get out and check out some tanks. sounds like it's time for a tank crawl...

 

[DJM28064212]

Ok so what you are saying is that:
A T-5 Fixture with 2-6500 Daylight and 2-Actinics will have a more yellow color(maybe) and should have better coral growth
And a t-5 Fixture with 2-10,000 Daylight and 2-Actinics will have a whiter look and have slightly less coral growth
Am I correct in this?

 

[CaptainDave]

i think what matt and i were saying applies to T5 bulbs, but was focused more to halides. It depends on what brand of T5 bulbs you're talking about (D&D/Geisemann are the best), but most people running T5s are running either 2 Blueplus (blue bulb) and two Aquablues (11K, white bulb), or 2 Blueplus, one Aquablue, and one GE daylight bulb (65K). The GE daylight bulb is brighter and a lot cheaper than the Geisemann daylight bulb and is the exception.

There isn't really a good actinic in the T5 bulb right now, so that's why most people are running Blueplus. They will give you a little different look, but still very nice. URI/UVL is coming out with a T5 actinic soon that is supposed to be really nice.

Are you looking at a pre-made hood or are you going to DIY it? My lights are a combination of VHO and T5, and I have one Aquablue and one Blueplus over my tank, plus a URI 50/50 VHO and URI Super Actinic VHO.

If you want to swing by and check out what it looks like, you're welcome anytime. I live in Fox Ridge, I'll PM you my number.