# Any PAR on A150W kessil amazon sun ?



## samamorgan (Dec 31, 2011)

I have contacted kessil on all of their current offerings, and they weren't too upfront with any helpful information. I ended up finding some information about the reef version, as kessil simply didn't respond with anything useful, one of those "we dont know and we don't want you to share this email" sort of replies.


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## propsi (Oct 5, 2009)

The PAR values you posted your "compedium" thread suggest that the Kessil is a serious light. I am concerned however about uneven lighting if one has to keep the light low for adequate PAR. Too bad that the company is not more forthcoming.


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## Steve001 (Feb 26, 2011)

What they say on their site is this light has a blend of wavelengths, but this is particular led has the same spectrum distribution as all other white led's currently adapted for aquatic plants. It could use higher output at 720 nm I think








6700K* Special Blend
Bring the power of the sun to your freshwater tank. This model is a true 6,700 K light that promotes lush plants and vibrant aquascapes.








I wonder is incorporating an led with this output into an led system would skew the color to an unacceptable level.


> http://www.kessil.com/images/products/h150w


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## propsi (Oct 5, 2009)

Steve001: I'm not sure I quite understand your point, but my understanding __and I am no physicist__is that adding a light to an existing setup would only result in an addition of intensity of specific wavelengths. One could not skew (create) colors not already present in either light. If both lights are appropriate in spectral terms, adding them would not result in unacceptable color. Sorry if this seems too simplistic...

You do raise an interesting point however. Even though Kessil's spectral output does, roughly speaking, resemble that of other leds I welcome the addition of a light with this particular format (i.e. a point source) specifically oriented towards the freshwater crowd. It seems that every new light that comes out on the market these days is saltwater specific. 

All we need now is evaluative data. More specifically: how close would one have to place this lamp to get acceptable PAR and how uniform would the lighting be at that height ?


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## Steve001 (Feb 26, 2011)

propsi said:


> Steve001: I'm not sure I quite understand your point, but my understanding __and I am no physicist__is that adding a light to an existing setup would only result in an addition of intensity of specific wavelengths. One could not skew (create) colors not already present in either light. If both lights are appropriate in spectral terms, adding them would not result in unacceptable color. Sorry if this seems too simplistic...
> 
> You do raise an interesting point however. Even though Kessil's spectral output does, roughly speaking, resemble that of other leds I welcome the addition of a light with this particular format (i.e. a point source) specifically oriented towards the freshwater crowd. It seems that every new light that comes out on the market these days is saltwater specific.
> 
> All we need now is evaluative data. More specifically: how close would one have to place this lamp to get acceptable PAR and how uniform would the lighting be at that height ?


Plants need light down to a PAR wavelength of 720 nm too. White LED's, the above included look somewhat weak at that wavelength. 

It is possible by having a strong peak output at any wavelength to create a light that skews the colors of objects the light reflects off even though other wavelengths are also being emitted. So it's necessary to have a balanced ratio across all wavelengths be emitted so the light looks apparently white to us and presents objects as naturally as practical.
Now I don't know what the lumen output of that particular red led is so adding it could create a source of light that appears warm. This wouldn't be bad for plants but it would not be a light that looks white and presents the colors of objects as naturally as practical. Since no led I know of has a spectrum that produces a truely smooth or nearly smooth white light based upon spectral output a blend of led's to fill in those weak places would be a good idea. Even a peak in the green/yellow portion of the spectrum would be useful because it would give the appearance of creating a bright tank without it actually being too bright for plants. It also make green plants look greener. Visual aesthetics is important too me.


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## propsi (Oct 5, 2009)

> Steve001]It is possible by having a strong peak output at any wavelength to create a light that skews the colors of objects the light reflects off even though other wavelengths are also being emitted. So it's necessary to have a balanced ratio across all wavelengths be emitted so the light looks apparently white to us and presents objects as naturally as practical.
> Now I don't know what the lumen output of that particular red led is so adding it could create a source of light that appears warm. This wouldn't be bad for plants but it would not be a light that looks white and presents the colors of objects as naturally as practical. Since no led I know of has a spectrum that produces a truely smooth or nearly smooth white light based upon spectral output a blend of led's to fill in those weak places would be a good idea. Even a peak in the green/yellow portion of the spectrum would be useful because it would give the appearance of creating a bright tank without it actually being too bright for plants. It also make green plants look greener. Visual aesthetics is important too me.


Gotcha. You're talking about the color quality of the reflected light. Thought you were talking about incident light. Yes, one would hope that Kessil thought about the color aesthetics. That's another thing to check.


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## samamorgan (Dec 31, 2011)

They actually don't need light in the 720nm wavelength. They can use it, but it's not necessary for growth.


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## Steve001 (Feb 26, 2011)

samamorgan said:


> They actually don't need light in the 720nm wavelength. They can use it, but it's not necessary for growth.


You are right but the research I've done indicates it would be more beneficial having it than not having it.


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## samamorgan (Dec 31, 2011)

It's beneficial, but not to a degree that you should really strive for. You wouldn't notice any quantitative differences in growth, unless you're really overdriving things like marijuana growers do.


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## pwolfe (Mar 2, 2011)

I would like to know how the light spread is on these is. Is there a hot spot?

I did see a video review where 2 were in use and I thought it looked great


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## silvawispa (Oct 11, 2011)

Can anyone conclusively confirm whether Kessil are doping LED's to create specific peaks in the colour spectrum tuned for plant growth, or are they just using standard technology and obliquely implying that they are doing something different.

In short, is this just marketing. (my gut instinct, looking at the graphs, is that this is all marketing and no new tech.)


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## pwolfe (Mar 2, 2011)

Well I did some research on these. If we can assume they have the same spread as the saltwater/reef versions, we can expect about 18-24" of spread and up to 30" depth penetration. There is also no hotspot. Could be an expensive, albeit effective alternative to par38 style setups. I'm getting really tempted to try them for my upcoming build.


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## propsi (Oct 5, 2009)

I've decided to try my luck. Put in an order for 2. I will give you my impressions when I receive them. I won't be able to give you any PAR numbers though: the Apogee quantum meters sell for $450 in these parts! (and the canadian dollar is on par_no pun intended_ with the US dollar). That's $150 over the price I'm willing to pay.


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## pwolfe (Mar 2, 2011)

hey propsi, did you get the lights?


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## samamorgan (Dec 31, 2011)

You can get a PAR reader that you just hook up to a multimeter for readings for $150 online, made by apogee.


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## propsi (Oct 5, 2009)

Just started a new thread.


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## propsi (Oct 5, 2009)

samamorgan said:


> You can get a PAR reader that you just hook up to a multimeter for readings for $150 online, made by apogee.


The sensor alone is $200 in Canada. I can't understand why manufacturers consistently overprice these things when it comes to selling products here. A PO really. I'll probably shell out the bucks eventually.


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## Achae3030 (Aug 25, 2013)

I took some readings on my 110 L "cube-ish" tank. I sent them to Kessil about a year ago. This is what I sent to them.
Bump:Mr.Aqua Cube.

At 7'' above glass, 22-25'' above substrate
- approx. 58μmol/m2/s directly under the light
- approx. 40 at the front of the tank (both left and right)
- approx. 25 at the back of the tank (both left and right)

Light suspended slightly towards forground.


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## jeffkrol (Jun 5, 2013)

propsi said:


> The sensor alone is $200 in Canada. I can't understand why manufacturers consistently overprice these things when it comes to selling products here. A PO really. I'll probably shell out the bucks eventually.


apogee's are fairly bad for LED's..
http://www.apogeeinstruments.com/light-intensity-measurements-for-light-emitting-diodes-leds/











apogee sensitivity is the flat topped blue line..


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