6700K, 10000K, Actinic...

[jack]

Re: 6700K, 10000K, Actinic...

so by running a 36w 10,000k light on my 20g, im starving my plants of light? should i switch to 6700k asap? should i run 2 36w 6700k bulbs in the tank if im dosing excel? sorry for all the questions but this is something ive been tryin to figure out.

[finfan]

Re: 6700K, 10000K, Actinic...

wow, this is good info. i don't know anything about K and such, i know my current T5HO is 6500K (54*2watts)!

[Zulaab]

Re: 6700K, 10000K, Actinic...

Jack you are going to want to install only one 6700k + 10000k and that would be your best solution.  Unless you are showing plants not growing right I would just wait until the bulbs are 1 yr old and replace both, one 6700k and one 10,000k

[Mzungu]

Re: 6700K, 10000K, Actinic...

jack - who said you were starving your plants of light??

The point is that K ratings on bulbs are for human eyes. Spectral power distributions tell you the actual "quality" of the bulb's spectrum. Take into account my post from April 29th...K ratings don't tell you much about the actual spectral distribution of the bulb.

[CichlidFan]

Re: 6700K, 10000K, Actinic...

I was under the impression that kelvin was an measurement of engergy or heat....not color....or is color/light considered to be engery in this instance?

CF

[Mzungu]

Re: 6700K, 10000K, Actinic...

Not sure I understand your question, CF?

In this sense, though, we're not referring to degrees Kelvin, but Kelvin ratings. Nacra said it well:

"The proportion of blues and reds translates into a unified visual color which our eyes perceive as a single color (say white light), which we identify with a "K" rating."

[CichlidFan]

Re: 6700K, 10000K, Actinic...

It's not a big deal to me at this point, but I was trying to imply that kelvin in my experience was a scale for heat or engergy.

This concept of measuring light bulbs with a kelvin rating is new to me....

CF

[J-WS6]

Re: 6700K, 10000K, Actinic...

lot's of good info here, this should be a sticky or something...

[nacra99]

Re: 6700K, 10000K, Actinic...

so by running a 36w 10,000k light on my 20g, im starving my plants of light? should i switch to 6700k asap? should i run 2 36w 6700k bulbs in the tank if im dosing excel? sorry for all the questions but this is something ive been tryin to figure out.

jack, nope.. you are not starving your plants of light.
10,000K looks bluer because there is more blue wavelength than red, but it still has enough red for the plant to use.

also, if you're running 36W, i'm guessing that you must have some sort of CF lighting. The intensity of CF lighting is usually enough to overcome the lower proportion of red spectrum. Just that you'll have a lot of blue that the plant won't be able to use.

Sorry if this is confusing.

[nacra99]

Re: 6700K, 10000K, Actinic...

I was under the impression that kelvin was an measurement of engergy or heat....not color....or is color/light considered to be engery in this instance?

CF

Actually.. you're kinda right with the heat comparison. "Kelvin" is indeed a measure of temperature. The reason it is used in lighting and aquaria is because someone decided to heat a block of carbon up to super hot temperatures and still managed to get close enough to look at and record the color of the hot carbon.

Simply, when used in lighting, "Kelvin" is actually the color of the carbon block at a particular temperature.

For example if you heat a carbon block to about 3000K (about 5000 F), the block will take on a nice reddish color, at 6000K (about 10,300 F), the carbon will begin to glow like the color of the midday sun.
The more you heat up the carbon ("increase the temperature"), the bluer it becomes... hence the correlation with the "kelvin" rating that we use in lighting.

So if you want to grow coral at 14,000K (lighting), you should take a chunk of carbon and suspend it over your tank, and put a blowtorch to it until it reaches 14,000K (24,700 F).
Or you could just buy a MH bulb rated at 14,000K.

I personally think the carbon block method would be more fun.

[jack]

Re: 6700K, 10000K, Actinic...

so do you think itd be better to run a 67k and a 50/50 10k/actinic than just my 10k and my actinic? that way id have more of the light spectrum but still have a little actinic cuz i like how it makes the colors pop

[nacra99]

Re: 6700K, 10000K, Actinic...

so do you think itd be better to run a 67k and a 50/50 10k/actinic than just my 10k and my actinic? that way id have more of the light spectrum but still have a little actinic cuz i like how it makes the colors pop

Is this a FW tank? Actinics are not going to help plant growth much, but you may keep it if you like the looks.
Between the 2 choices above, for fresh water, i would go for the 67K + 50/50 rather than the 10K + Actinic.
For salt water i would go with 10K + actinic.

[jack]

Re: 6700K, 10000K, Actinic...

ya its a fw tank. if i do add co2 itd be best to go wtih 2 67k bulbs right