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Well, the reason it might look a little pinkish is because most bulbs have a wide spectrum. The K reading may only tell where the light peaks. jake may be getting light from the voilet area of the spectrum or there could be a mixture of colors that could be creating a "pinkish" or maybe a voilet look.

Many bulbs above 7500K are made for marine and reef application. These are situations where you would want light from the violet area of the spectrum. This is because the light with a shorter wavelength is the only light that makes it throught the water deep enouigh to reach reefs in the ocean.

As the pictures on the bottom of this page http://www.equarium.com.au/store/category.asp?catid=23, the light of the actinic is mostly in the blue. I am not sure, but many claim the blue light is very good for plants. The only drawback to this is that this type of lighting is also good for algae. So depending your algae fighting skills, this may not be a problem.

Thanks for the advice Dragon. I may go out and buy a daylight/sunlight ~6700k Bulb like you said

When you are talking aboutr color temp, this does not tell you the entire spectral output.
For Example, the Atinic blue 7100K is primarily just this narrow color spike in the blue region and virtually no red or other color mix.
You can use a Triton which has a blue and a substantial amount of red and has a color temp of 7200K.
A 10K bulb also appears white becuase of the mix of colors.

Plants will use light in the 400-700nm range. So will algae..........Light is light, 6500K bulbs do not grow plants any better than 4100K watt for watt of energy.

How the colors appear to our eyes is another matter.
But the plants and algae can and do adapt to the light that is there, they can use yellow and green light also, chlorophyll is not the only light harvesting pigment.

You can talk a long time about light color temps and algae prevention(but both have the same type of chloroplast and internal machinery) and so forth, but ultimately it's a question of how it looks to your eyes. Most of us like 5000-10K range. So whatever floats your boat in that range is good.

Regards,
Tom Barr

Yet another insightful reply, thanks Tom!

Plants are more photosythetically sensitive to the red and blue light. I guess that is how I should have worded it.

Also, blue light might be a better option for deeper tanks since it doesn't get absorb as easily through the water. As plants grow to the top of the tank they may be able to use the red more. This might explain why some of my plants grow better as they reach the upper half of the tank.

Fish can handle much brighter light. Heat and the temp. of your tank water is something to take into consideration. You might not have a problem with the smaller bulbs you have but keep an eye on your therm.

You may hear the light temp. and light wavelength used interchangeably. K is temp. Red is cooler, then orange, yellow, green, blue, and then violet being the hotest. Just like on the spectrum charts you may have seen. nm is the wavelength and can be visuallized by thinking of a sine wave. The wavelength is the length of a complete cycle of a wave as it travels through a medium. The higher the temp. the shorter the wavelength.

Oh, if your taking the quiz on this site, they seem to leave some of these colors out in one of their questions "what colors of the spectrum are used with aquariums" or something like that. Just pick the answer with the most colors I guess. I thought it might be white since all the colors in the spectrum combined makes white and all the colors can be used for one thing or another, but that was wrong.

FMZ, did you get my PM?

No Dragonfish I did not get your PM except the first one. Did you get my reply??

sly, k rating determines the COLOR of your light.

and wattage determines the intensity of yer light

Best bulbs for plants would be ones that peak at the blue, green, and red. The blue and red are for the plants to stay healthy and the green is to give the leaves and aquarium a better look. Usually, daylight bulbs (or bulbs around 6500k)do pretty much that.

Mixing bulbs can also be an option. On my tanks I will mix P&A and daylight. This gives very good grow lighting and I still get more daylight colors to make my tank look more natural.

In your case, you can keep one of the 9325K in the double strip and change the other bulb to a daylight. Save the other 9325K for when it is time to change your bulb (about a year). The other single bulb light strip you can keep whatever it is unless you want to experiment with a P&A bulb or something else.

[span class="edited"][Edited by dragonfish 2004-07-10 11:40][/span]

I use acitinc blue and I really dont have much problem with algae. Usually my Otto and BN takes care of it. I love them guys

My plants are growing very well, i have so many green camboba or whatever you call it that I am thinking about tossing it. I have like 5 lilys that are covering the whole aquarium. I am thinking about tossing them out too or cutting them. i have some red plant that i can't id and some web like plant that i can't id as well. when i bought it from lfs, it was in okay shape, now its growing and its full of new leaves that are bright green. I have some fern that i cant identify which has some new green growth on it. Also, for the first time, Java moss is growing and i can see new bright leaves on it.

i consider moving some of my plants to my 30 gallon but i only have 2 18W compact flor. on it.


I bought the lightning equipment last month, so i'll change the lights on it next year. I am using a DIY CO2 for now as I am short on budget. I am using 1 2.5 liter and 1 Gallon bottles on my DIY CO2. So far I am happy with it.

Its odd that GE 9XXXK bulbs looks red to me. Anyways, I have 2 10,000K PC and 2 Acitinic blue PC on my aquarium with one Eclipse Daylight NO bulbs. The Eclipse bulb it seems have a K range of somewhere between 5000-6000k since its pretty yellow.

The reason I haven't changed the acitinic blue bulbs on my PC strip is because I have read that blue causes the plants to grow more thicker bushes while the red causes them to grow longer. So I am using acitinic and it doesn't look bad at all.

Thanks Jake, I read your entire post! ]

Basically, if there's no K rating on the bulb, just get a "natural daylight" bulb.

If plants use the Red and Blue specturm more, plants will definatly like Actinic Blue then since it peaks in Blue

That is a topic of great debate. Actinic peaks at 420nm, which is a narrow spectrum, supposedly. It's not suggested for growing freshwater plants for this reason ( narrow spectrum). However, people that say it does NOTHING for freshwater plants are not entirely correct, ...but it is certainly not an optimal choice, with so many wide-spectrum bulbs out there to chose from. To aquariasts that are very serious about their plants ( some of which are probably a little cookoo about them), the nominal benefits plants receive from actinic lighting, in their minds, is too low to be considered an option. Therefore, when they speak about it, they say it does NOTHING for freshwater plants, because to them it doesn't , although science might say it has to do SOMETHING. It's like being hungry as heck and eating a single potato chip and saying that did " nothing " for you... but it gave you 10 calories, added x amount of salt to your bloodstream, caused your mouth to water, set off a digestive chain of events, etc.

What it boils down to is that it's blue, and plants might like the blue, but it's almost TOO blue. That's what I get out of reading all the scientific mumbo jumbo anyway. That and people don't like the way they look in freshwater tanks. For those reasons, many aquariasts dismiss them outright for freshwater purposes.

As for the K ratings , I copied this from Type-R , a moderator from plantgeeks.com. "Lower kelvin = more red
Higher kelvin = more blue

The kelvin range is just a a reference for how a lamp appears to our eyes. It is derived from the colour which a theoretical black body glows when heated to x temperature. It effectively ranges from where the first faint red glow appears right up to 28,000K which is meant to be the blue colour of the North sky. On the kelvin colour scale nominal sunlight is 5600K.
What we must realise is that referring to a fluorescent lamp as having a kelvin colour is inherently wrong. The kelvin colour range only applies to those objects which emit energy across the whole visible spectrum. Incandescent lights are a good example of this as is sunlight.
A fluorescent lamp only emits energy in 'peaks' at specific wavelengths, this means the Kelvin colour range cannot be used to represent the colour of the light emitted.
So no matter what kelvin the manufacturer puts on a fluorescent lamp it isn't going to be correct.
When choosing lighting for growing aquarium plants all we can do is bear in mind that virtually any fluorescent lamp will grow plants, the exceptions being actinic, moonlight and other 'special lamps'.
The amount of lighting is the most important factor, some lamps do appear to grow plants more successfully than others and luckily we have boards like this one where people can share their experiences of certain lamps.

So in summary you should choose the lamp which gives the 'look' you like most, be it labelled 4000K or 18000K, or you can follow what other people use.
As long as you have enough lighting you can grow plants. "

The link to that thread is
http://www.plantgeek.net/forum/viewtopic.php?t=1218&highlight=actinic

Sorry for the long post. Having used every compact fluorescent bulb kelvin rating there is, including 50/50 ( half 10000k, half actinic) to grow plants, I had to comment on the actinic thing and just didn't know where to stop.

[span class="edited"][Edited by jake 2004-07-10 00:51][/span]

If plants use the Red and Blue specturm more, plants will definatly like Actinic Blue then since it peaks in Blue

Cool thanks!

9325k are 'supposed to be' in the blue spectrum, but I have three 9325k compact fluorescent bulbs running at my house and they don't "look" blue. They look pinkish. I use two of them and two 6700k's on my 75 gallon as they mix very well ( at least to my eyes they do). Below is a pic of 9325k...it looks the same color as it shows in the picture.
jake attached this image:
[img]http://www.fishprofiles.net/attachments/392977.jpg"]

yeah, they are low. I think they may spike around the yellow which isn't very useful.

i think cool white is pretty low in color temp, something in 3000's? day light and sun light are the ones with highest color temp. and they got good ones at pet stores too, but they are a bit pricy