FishProfiles.com Message Forums

can anyone direct me to spectra for a 10000K? i've been given one of these and i wanna make sure what im subjecting my plants to. looks much more blue than my standard 18,000K that i use. is it a marine bulb?

the higher the number the more blue the bulbs are. so your 18,000K should be more blue. Generally you should use 6700K bulbs for plants. that is considered a midrange bulb wich is closest to actual sunlight.

there are so many views on that particular subject this thread could go on forever if it opened up into it. most people say 6700K because they find it more aesthetically pleasing. mind you im not even sure that ive ever seen a 6700K bulb around only ever seen 18,000K for sale. i have a 15000K in my roof atm aswell. certainly the best lighting iv ever had.

10,000k are fine for plants. It's a matter of aesthetics, or maybe how deep is the tank.

I've used all 10K, and all 6700k at various stages. Both pretty much worked as well as the other interms of growth and plant health.

I wasn't totally happy with the look of 10k and swapped out to all 6700k which i was much happier with the color rendition. But as I have a deep tank the lower plants were struggling a bit with this set up. I have now settled on 2 x10k bulbs and 2 x 6700k which seems to be a decent comprimise.

I also had 12000k at one stage (bulbs were already in the fitting) again growth was fine but I absolutely hated the look.

The 18k bulb does have more blue but that may not neccessarily be picked up the human eye.The human eye is totally unreliable when judging spectrum (except to tell you if you like the look or not)

There's a school of thought (which I tend to agree with) that spectrum is not that inportant and that intensity is the key factor.

---

Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

I have a lighting setup that came with 10,000K 65 watt tubes, and for a 30 gal. tank less than 20 inches tall, this light is really too powerful, as many of my plants tend to grow horizontally rather than stright up, and instead of turning a pleasent pink at the tips, they fade to a yellowy color. If I was cultivating a mini reef, my anenomes would be very happy, indeed, but all of my plants look stunted and weird.

Hoping that there must be a word for everything I mean...

I seem to remember reading somewhere that blue light makes plants grow outwrds or bushier and that red makes them grow taller.

Or I could have that the wrong way around !

As I mentioned above the human eye is relatively lousy at judging light. A 30watt 6700k and 30 watt 10000k produce pretty much the same amount of light (assuming the lumens output is similar) but the 10000K will look brighter as the human eye can see the spectrum easier. Just because we cannot see the light doesn't mean it's not there.

---

Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.