Kelvin

[snowmansnow]

ok, KELVIN isn't someone's name in this case, but color temp.

STUPID QUESTION here, but I figure.. hey... why not.

so.

Let's say someone want's a 20K look in their tank (very common). But hes a T5 gent like myself and deals with 7-10 T5 lamps combined to try and come up with the right K.

Is there an equation for the combined lamps that = ? What I mean.. is..

Lets say you have a 10 k lamp and a 5 K lamp... well the total K isn't going to be 5 K....

Can you take the average, or the median? what? I assume the look would be around 7K...

what if you have 10 lamps? Is there a reasonably accurate way to estimate what the average K would be?

B

 

[clay4au]

One thing to keep in mind is companies can put whatever K they want on the package so one company's 14k could be bluer than another's 20k. The spectral graph is something more definite to go by.

 

[ksicard]

I would just go with whatever bulb combo is best for growth on your tank and add a strip of royal blue led's and then dim the led's to whatever looks best to you. I think that would be your best bet for achieving a blue spectrum that you want, also you can always change the kelvin this way as long as you added dimmable led's.

 

[snowmansnow]

I'm just not into LED:/
It takes a LOT of LED s to not get washed out w my t5

But thanks for the idea

 

[skriz]

There are far superior t5 options to waste your time with led supplementation.

Each manufacturer rates their lamps differently, so a straight equation won't really work. Unfortunately, it's a process of trial and error. I have a combo that looks sweet. I'll dig it up when I'm back and let you know; see how you like the look.

 

[sn4k33y3z]

SnowManSnow;869975 wrote: ok, KELVIN isn't someone's name in this case, but color temp.

STUPID QUESTION here, but I figure.. hey... why not.

so.

Let's say someone want's a 20K look in their tank (very common). But hes a T5 gent like myself and deals with 7-10 T5 lamps combined to try and come up with the right K.

Is there an equation for the combined lamps that = ? What I mean.. is..

Lets say you have a 10 k lamp and a 5 K lamp... well the total K isn't going to be 5 K....

Can you take the average, or the median? what? I assume the look would be around 7K...

what if you have 10 lamps? Is there a reasonably accurate way to estimate what the average K would be?

B

Yes, you would take an average! However, depending on the output of each lamp could affect the "CRI".

"Kelvin is defined by two points: absolute zero, and the triple point of pure water. Absolute zero is defined as being precisely 0 K and -273.15 °C. Absolute zero is where all kinetic energy (motion) in the particles comprising matter ceases, and they are at complete rest. At absolute zero there is NO heat energy (the total absence of heat). Water freezes at 0 Kelvin, and water boils at 373.1339K or 100C.

The true definition of Kelvin is that it is a unit of measure of temperature on the thermodynamic (absolute) temperature scale."

"Different nanometer wavelengths can be used to reach the same Kelvin Temperature; just as 4+5 & 1+8 both equal 9, so can different nanometer wavelengths be used for the same Kelvin Temperature. This is why often comparing one 6500K lamp to another can often be "apples to oranges" as for necessary useful light energy (PUR) needed by plants or corals
."

 

[heathlindner25]

Sn4k33y3z;870085 wrote: Yes, you would take an average! However, depending on the output of each lamp could affect the "CRI".

"Kelvin is defined by two points: absolute zero, and the triple point of pure water. Absolute zero is defined as being precisely 0 K and -273.15 °C. Absolute zero is where all kinetic energy (motion) in the particles comprising matter ceases, and they are at complete rest. At absolute zero there is NO heat energy (the total absence of heat). Water freezes at 0 Kelvin, and water boils at 373.1339K or 100C.

The true definition of Kelvin is that it is a unit of measure of temperature on the thermodynamic (absolute) temperature scale."

"Different nanometer wavelengths can be used to reach the same Kelvin Temperature; just as 4+5 & 1+8 both equal 9, so can different nanometer wavelengths be used for the same Kelvin Temperature. This is why often comparing one 6500K lamp to another can often be "apples to oranges" as for necessary useful light energy (PUR) needed by plants or corals
."

huh??

 

[sewer urchin]

Hey B

I've wonder about this one myself, but never got around to asking (new to t5, though been reefing for years. It's amazing how fast technology grows when you are not involved with it daily). Thanks for asking so that I didn't look like a complete newb.

 

[rdnelson]

Makes perfect sense to me. By the way. Who is Kevin. Isn't that a goat?

Seriously, that explanation is right on the money.


Sent from my iPhone using Tapatalk

 

[sn4k33y3z]

Lets say you have a 10 k lamp and a 5 K lamp... well the total K isn't going to be 5 K....

Can you take the average, or the median? what? I assume the look would be around 7K...

what if you have 10 lamps? Is there a reasonably accurate way to estimate what the average K would be?

B[/QUOTE]

With 10k and 5k lamps you could never acheive 20k... Remember it's based on temp! What you could do is, get an accurate fahrenheit temperature reading (easier said than done, because you'd need to know what each bulbs fahrenheit temperature is) and convert the TOTAL fahrenheit temp to kelvin.

K = 5/9 (° F - 32) + 273

 

[snowmansnow]

The reason I asked the question:
What if there was a standard for Kelvin in the aquarium hobby.

And an aquarist was able to go to a website and look up different k readings for his / her new tank, and then just purchase lamps to achieve that goal.

How much head scratching and trial would THAT eliminate.

Here's my new lamp configuration.
It is 7 lamp. The pic is pretty true to life for the color.

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Pardon the algae...
What k is it? Who knows haha.

 

[snowmansnow]

Here is a 6500k GE
+
6000k KZ

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Here are the same 2 lamps + 2 ATI Aquablue Specials

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Here are the same 4 lamps + 3 ATI Blue + lamps.

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[heathlindner25]

Time to clean that acrylic....lol

 

[ichthyoid]

To the OP, short answer is no.

There is not a formula for calculating the 'sum' of Kelvin ratings from different lamps.

To determine the Kelvin rating of a light source, a measurement must be made using a calibrated quantitative spectrometer.

 

[ichthyoid]

Sn4k33y3z;870085 wrote: Yes, you would take an average! However, depending on the output of each lamp could affect the "CRI".

"Kelvin is defined by two points: absolute zero, and the triple point of pure water. Absolute zero is defined as being precisely 0 K and -273.15 °C. Absolute zero is where all kinetic energy (motion) in the particles comprising matter ceases, and they are at complete rest. At absolute zero there is NO heat energy (the total absence of heat). Water freezes at 0 Kelvin, and water boils at 373.1339K or 100C.

The true definition of Kelvin is that it is a unit of measure of temperature on the thermodynamic (absolute) temperature scale."

"Different nanometer wavelengths can be used to reach the same Kelvin Temperature; just as 4+5 & 1+8 both equal 9, so can different nanometer wavelengths be used for the same Kelvin Temperature. This is why often comparing one 6500K lamp to another can often be "apples to oranges" as for necessary useful light energy (PUR) needed by plants or corals
."

You are confusing the temperature scale of 'degrees kelvin' for 'color temperature Kelvin'. They are NOT the same thing.

One measures temperature, in degrees.

The other measures 'color temperature' (without any 'degrees').

The latter is based on 'the spectrum' created by a standard reference, which is platinum wire heated to a specific temperature.

Ex: 5,000 Kelvin
(there are no 'degrees' indicated, as this is what is called a dimensionless number).

Hope this helps.

 

[sn4k33y3z]

ichthyoid;870152 wrote: You are confusing the temperature scale of 'degrees kelvin' for 'color temperature Kelvin'. They are NOT the same thing.

One measures temperature, in degrees.

The other measures 'color temperature' (without any 'degrees').

The latter is based on 'the spectrum' created by a standard reference, which is platinum wire heated to a specific temperature.

Ex: 5,000 Kelvin
(there are no 'degrees' indicated, as this is what is called a dimensionless number).

Hope this helps.

In a flourescent application, a light bulb uses GAS. Depending on the gas temperture in the light bulb determines the Kelvin (color temperature). I stated the formula above to equate kelvin. In order to get- lets say 20,000k (kelvin) what are you suggesting the formula is to acheive the "kelvin color temperature" for 20,000k lightbulb is? Also, what are you suggesting is the determining factor of color when speaking about light bulbs that varies the color rendering... Watts... No... Voltage... No... Please help me understand your logic.

 

[snowmansnow]

End up in Rome one day and we Dan work something out. It's a tort

 

[ripped tide]

http://media.tumblr.com/89eee628ac13a6c6a9be123a4fd35e7c/tumblr_inline_ml5smkaapG1qz4rgp.gif" alt="" />

You wanted a "cooler" kelvin temp, right?

 

[sn4k33y3z]

Ripped Tide;870221 wrote: http://media.tumblr.com/89eee628ac13a6c6a9be123a4fd35e7c/tumblr_inline_ml5smkaapG1qz4rgp.gif" alt="" />

You wanted a "cooler" kelvin temp, right?[/QUOTE]

LOL that's awesome!

 

[ichthyoid]

Sn4k33y3z;870175 wrote: In a flourescent application, a light bulb uses GAS. Depending on the gas temperture in the light bulb determines the Kelvin (color temperature). I stated the formula above to equate kelvin. In order to get- lets say 20,000k (kelvin) what are you suggesting the formula is to acheive the "kelvin color temperature" for 20,000k lightbulb is? Also, what are you suggesting is the determining factor of color when speaking about light bulbs that varies the color rendering... Watts... No... Voltage... No... Please help me understand your logic.

Here's a link explaining the heat or temperature kind of kelvin (a 3rd type scale, in addition to Farenheit and Celsius)-

http://en.wikipedia.org/wiki/Kelvin">http://en.wikipedia.org/wiki/Kelvin</a>

Here's a link explaining Color Temperature-Kelvin (notice there are no 'degrees' involved)-

[IMG]http://en.wikipedia.org/wiki/Color_temperature">http://en.wikipedia.org/wiki/Color_temperature</a>

As to your comments on flourescent bulbs-

In a flourescent bulb, heat has little to do with generating the light, other than there is an optimum temperature for the following-

Instead, a bead of mercury about the size of a pin-head is ionized by an electrical current running through the vacuum filled tube. The ionization process results in vaporization of the mercury and subsequent production of UV (~254 nM) being emitted by the ionized mercury. That UV is then absorbed by phosphors coated on the inside of the bulb, causing them to flouresce. The amount and types of phosphors determine the wavelengths of light emitted. Not the temperature.

[IMG]https://en.wikipedia.org/wiki/Fluorescent_lamp">https://en.wikipedia.org/wiki/Fluorescent_lamp</a>

I hope that this helps clear things up a bit. There are many people that read these posts, and accuracy is for the benefit of all.