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It is time to replace my current fluorescent bulbs and I was wondering what colour temp the new ones should be. Its a 32g tank with two 24 inch bulbs. The length of the tank is 31.5 inches and I dont want to replace the hood so the lights dont cover the whole tank length. Currently I have one bluish tint bulb and one with a redish tint. Not too sure about the K on them since i threw out the packaging a year ago. I think one is around 10 000k and one is below 5 000k. I have plants in my tank so one will be 6700k. What should the other be? The tank is 18 inches deep.

Eric,

based on a tip that I got from Untitled, I would suggest the 5,000 K light in addition to the 6,700 K.

I have not tried that out yet, I am in the process of getting my pieces for the 125G together. I have ordered the above mentioned bulbs and will experiment with them (I will have 10,000, 6,700, 5,000, and Actinic to play with) until I find the right combination for my tank.

Hope this helps,

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

Well I am currently unhappy with the current light fixture because it has no glass over it and the lights are about an inch from the water, so it the lights get covered in moisture. What should I do with that. I may also change to PC lights in the future so I am doing more research on this. But for now I will stick with the NO fluorescents. To my understanding bulbs with a low kelvin rating are more of a red tint and ones around 6700k are white, simulating daylight and ones above that are more blue?

Edit: And what is actinic?

Last edited by ericm at 01-Sep-2005 15:12

Actinic if I remember correctly have an even higher kelvin. From what I've read they are rated to increase algae growth in SW tanks. However I've also seen some say that they've had no problems with them in FW tanks *shrug* clarification of course would be good!.

Personally I prefer not to have my tanks look funny colors, which is why I stick with 6500-6700K daylight bulbs. That and the fact that they're $5 @home depot .

^_^[hr width='40%']"Has someone taken your faith? It's real, the [link=pain]http://babelfish.qwertydigital.com/" style="COLOR: #EB4288[/link] you feel.
The life, the love, You die to heal.
The hope that starts, The broken hearts...
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I’m getting tired of starting again, Somewhere new."

And thats where I am going to get them . The lights i got came with the hood and I am not sure but one may be around the 10 000k area and it looks really good. I still am not sure what the other bulb should be. Should I just get two 6700k bulbs?

If you're going with both bulbs on @the same time, I personally would stick to two matching ones. I've mixed different kelvin before and it can look okay, it can also make the tank seem spotty and uneven. This of course is purely a visual decision. I know others feel strongly about using blue light for reaching the bottom in deeper tanks and all that. I feel that unless you have a signifigantly deep tank (say over 2' tall) it isn't really needed.
The only time I'd use different bulbs is if they were on timers to be on @different times (ie moonlighting).

^_^[hr width='40%']"So take the photographs, and still frames in your mind.
Hang it on a shelf in good health and good time...
It's something unpredictable, but in the end is right
[link=I hope]http://babelfish.qwertydigital.com/" style="COLOR: #EB4288[/link] you had the time of your life"

And should I change the bulbs a week apart so the fish wont go into shock since the lighting will be different?

Never actually heard of that being done .

Cant see the harm in it really, although try just changing them both @once...if you notice that they seem to be rather stressed after a few hours you could try replacing one of the old ones, or just leaving the lights on for a shorter duration.

^_^
[hr width='40%']"So take the photographs, and still frames in your mind.
Hang it on a shelf in good health and good time...
It's something unpredictable, but in the end is right
[link=I hope]http://babelfish.qwertydigital.com/" style="COLOR: #EB4288[/link] you had the time of your life"

I will try that. I think I will go with the 6700k bulb and the 5000k bulb. I think the aqua glo i have now is way over 10 000k but it really brings out the fishes colours. The flora glo is more dull so I think its like 3000k. Hagen doesnt post their kelvin ratings for their bulbs online but it is on the packaging so i will go to a lfs later to see what the Ks are for the bulbs i have. I like the aqua glo tho so I may keep one of those sticking around.

Went to home depot and got a 6500k and 5000k for 5 bucks each. Only problem is the old bulbs are T8 and the new ones are T12 but they new ones fit... just a bit thicker. Will this be a problem though since they are T12 and not T8????

Bulbs under 6,500k will look more yellow not red and are not as useful for plant growth. They are designed for use in the home and lack the glare of sunlight. Unless they are specifically designed for plants and don't use the usual spectrum of a 5,000k bulb they will mostly contain yellow and green light while plants need blue and red light. Blue light doesn't actually seem to increase algae growth on it's own but plants can't use that much blue light by itself while algae seems to have better luck. If you balance the blue light with a redder light then the plants would use it more efficiently.
Bulbs rated 6,500k-10,000k usually contain the light that plants need and plant specific bulbs like aqua glo or flora glo won't follow the general rules as closely but will contain the spectrum plants need. These bulbs should both have alot of red and blue light, some yellow-orange, and minimal green light but I don't know what kelvin rating they have.

Well I ran into a slight problem. On my current hood the fluorescent lights must slide into a screw off socket cover too seal off any moisture from getting into the socket. The lights are directly exposed to the water. So the T12 bulbs i bought dont fit into these socket covers and the bulbs wont work unless the covers are screwed in. And home depot doesnt have the lights i bought in a T8 form in 24 inches. So what to do now?

Edit: I went to a lfs and chekced out the kelvin rating of the bulbs i have now. Aqua glo is 18 000 k and they didnt have the flora glo so I am not sure about that. Hagen has graphs of each colour wave lengths on their site also... and I will probably have to stick to specially made aquarium lights instead of the normal lights from home depot since they are commonly found in T12 for a 24 inch and not T8. So I will most likely stick with Hagen. Which 2 of these bulbs should I go with now? Each link will bring you to their site which displays a graph of colour wavelengths they include.

Aqua-glo

Flora-glo

Sun-Glo

Power-glo

Life-Glo 2

As for Kelvin ratings:

Aqua glo - 18 000k
Sun glo- 4200k
Power glo - 18000 k
Life glo - 6 700k




Last edited by ericm at 02-Sep-2005 19:25

Last edited by ericm at 02-Sep-2005 19:26

Eric,

The Aqua and Life Glo are on This Tank.

EDIT: Second Picture in the linked thread.

When the Aqua burns out I might switch to the Sun Glo.

Ingo

Last edited by LITTLE_FISH at 07-Sep-2005 19:28

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Proud Member of the New Jersey Aquatic Gardeners Club

Ingo which one is in the front? I havent tried life glo yet and I am going with one of thsoe. Too bad i just cant get those 6700k light sfor 5 dollars . Sun glo i think is a bit yellowish if i am current and its 4200k.