LED's by Ecoxotic?

[Cyclesafe]

As it's time for me to replace 2 96W 6700K CF bulbs for $68, I was thinking that for a few pennies more I could get one (or two) of these 13W 8000K LED fixture(s) for $99. They seem compelling:

• No scary DIY electric wiring around the tank
• 13W (or 26W) rather than 192W - significant power bill savings!
• Would make my wood canopy a tad lighter
• Reflector edges are contained so I would not cut myself on sharp metal edges
• The color would be more pleasing to me, as a human
• The shimmering effect would also be esthetically appealing
• Virtually no heating of the tank: there would be less temperature variation when lights are on and I wouldn't need a fan in summer (no more mid week top offs!)
• Bulbs last ~10-20X+ as long as compact fluorescents
• I wouldn't having to worry about generating hazardous waste (used mercury-containing CF bulbs) or chauffering dead bulbs to the HW accetance station at the dump.

Of course, I don't know how they'd function as a fixture for a low light 120 gallon planted tank. And of course, that's rather important.

I know what Ecoxotic thinks. What do you guys think?

 

[pdavis41]

They don't state what kind of light (lumens) output they provide. That is the only huge drawback that I can see.

Since you are running low light I could see a couple of these working for you. How long is your tank? You would need at least as many as it would take to cover the length of your tank. I'm guessing they are 1W LED's as there are 12 diodes for 13W. Can't really guess what PAR to expect until you can figure out what the output of the lights will be.

But they do look promising and easy to install if they can put out enough light!

 

[Cyclesafe]

4'x2'x2'. I have sent an inquiry to Ecoxotic asking for PAR values. I'll report back when/if they respond.

 

[SuperColey1]

They look OK however the maths doesn't add up!!!

[*]13W (or 26W) rather than 192W - significant power bill savings!

Yes you will save power with high power LEDs but if these are 1W x 12 how are they 13W units? Are they overdriven? If so they will burn out quicker

[*]Would make my wood canopy a tad lighter

Most definitely.

[*]Reflector edges are contained so I would not cut myself on sharp metal edges

Why do they need reflectors? LEDs only push light down and then lenses focus them. Even if the reflector is there to catch the sideways light that is much less efficient than lenses which is wierd. Lenses are cheaper than reflectors by a long way. Lenses direct all the light downwards much like the cone type reflector in a torch.

[*]The shimmering effect would also be esthetically appealing

The shimmering is nothing to do with LEDs. It is to do with multiple light sources. 12 smaller flourescents will give you shimmer. 2 flouros raised high enough will

[*]Virtually no heating of the tank: there would be less temperature variation when lights are on and I wouldn't need a fan in summer (no more mid week top offs!)

Anyone who knows high power LEDs knows this is wrong. they give off massive localised heat and then we use heatsinks to draw it off. Often couple with a fan. Mount a few of these on an aluminium bar and it will bend with the heat.

[*]Bulbs last ~10-20X+ as long as compact fluorescents

Exaggeration to say the least. Say 3x CF and 1.5-2x linear flouro on electronic ballasts

Of course, I don't know how they'd function as a fixture for a low light 120 gallon planted tank. And of course, that's rather important.

2 over a 120G is hopeful to say the least. You're going to need approx 1WPG LED to match 2WPG of CF.

They don't state what kind of light (lumens) output they provide. That is the only huge drawback that I can see.

Lumens is no use for us at all. Lumens is only what we can see, nothing to do with PAR. Add to that LEDs give out less Lumens per W but higher PAR!!!. a 75W Solaris gives out 85% the PAR of a 250W MH!!! It gives out 110% the PUR.....Ouch

Since you are running low light I could see a couple of these working for you. How long is your tank? You would need at least as many as it would take to cover the length of your tank. I'm guessing they are 1W LED's as there are 12 diodes for 13W. Can't really guess what PAR to expect until you can figure out what the output of the lights will be.

As a basic guide just work out you need a third to a half of the wattage of the CFs to match them. Also I would say you could use less than 192W of CF over your tank for low light.

 

[Cyclesafe]

AC,

You obviously know a great deal more about this than I and I appreciate your analysis. Where can I go to get the best instructions for a DIY project?

Also, your points about running one 96W CF bulb are well-taken. That's what I'm doing now - backing off from the four I used in the past.

Meanwhile, The Ecoxotic people came back with the following:

Dear Mr. Hayford,

Thank you so much for contacting Ecoxotic and showing interest in our LED products.

Although we understand many hobbyists have been told an aquarium requires a certain number of watts per gallon (WPG), it really is not a measurement of light output at all and we do not compare LEDs to CFs in this manner. In addition, PAR in CF’s will be very dependent on the color spectrum, ballast/driver used and manufacturer of the lamp.

We can tell you our Panorama Modules use 135 lumen/watt LEDs and most planted aquarium hobbyists use our 8,000K Panorama Modules. For a heavily planted 48” x 24” aquarium, we would recommend using 1 module per 12” (therefore 4 modules.) This will provide the same amount of light your currently using with 2x96w CFs.

If you have any other questions regarding our products, please do not hesitate to contact us. Once again, thank you for showing interest in our products.

Sincerely,
The Ecoxotic Team

 

[SuperColey1]

Just quickly a link to mine however it is on barrreport somewhere too. Mine is a bit of a non electrical knowledge effort in terms of power. Others would probably use a single plug and program a board to do the stagger where I use 5 DC adaptors with timers instead.

http://www.greenneedle.co.uk/LEDMKII1.html

Like I said above they are a little on the optimistic side in the reply they sent you.

PAR is light and nothing to do with spectrum. Lumens are affected by spectrum.

I think if they were using lenses then 4 is possible but why they are using reflectors I do not know.

AC

 

[nipat]

---
PAR is light and nothing to do with spectrum. Lumens are affected by spectrum.

---

Doesn't actually PAR depend on spectrum while lumen does not?

 

[SuperColey1]

An example of Lumens with Spectrum for a like for like LED unit just different colours:
Warm White: 3700 Kelvin; ~ 550 lumens - Yellowish Light
Natural White 4100 Kelvin; ~ 600 lumens - Slight Pink Light
Daylight White: 5500 Kelvin; ~ 650 lumens - Pure Day White
Cool White: 7000 Kelvin; ~ 650+ lumens - Bluish Light

source:
http://www.ledtape.com/LED-T8-Light-Tube-2-foot-180LED-8W-p/lt-ledt8-2-nw8w180.htm

If PAR ran with the K then it would mean if we use X colour we would need more LEDs than if we use Y colour which isn't the case as far as I know.

Its the (not so old) use what colour you like statement. If spectrum affected PAR we would be saying use X colour as it gives more PAR for less wattage consumption.

I would forget about the lumens figures on most light sales websites. They tend to put the same lumens on all the colours of a particular brand from what I can tell.

AC

 

[Jim Miller]

Both are measured with spectal effectiveness: lumens for people PAR for plants. Spectral curves are different.

Jim

 

[nipat]

Both are measured with spectal effectiveness: lumens for people PAR for plants. Spectral curves are different.

Jim

You are right. I've forgot that lumen/lux is derived from human vision.

If PAR ran with the K then it would mean if we use X colour we would need more LEDs than if we use Y colour which isn't the case as far as I know.

AC, not quite. Different spectrum combinations can yield the same color for our vision.
PAR does has spectrum involved. Two light sources with same color can give different PARs.

Kelvin is poor way to communicate. Because we don't know what spectrums combinations in it.
It's also a poor way to communicate color.

Look at page 2, 6000K can be yellow or pink. And by the same way, 10000K can be blue or pink.
http://docs.google.com/viewer?a=v&q...Lqvumj&sig=AHIEtbRdJGmvayh9gxXuw8XGCUa-5nE_5w

 

[SuperColey1]

I see your point there. I guess we often just simplify 'spectrum' by using the common known K that is most used for each colour?

However I can't see how it affects PAR unless the spectrum of the light moves the light frequency outside of the wanted range that PAR/PUR measure?

I would;ve thought that all lights in general use other than black lights, UV etc were within the measurable range and therefore equal in terms of PAR. Just that the actual light the PAR measured may be at different ends of the measured range?

AC

 

[nipat]

So there is no sensitivity curve involved in measuring PAR.
Because PAR is simply from the counting of all photon between 400-700 nm.

So I've been fooled by that fancy curve accompanying PAR articles.
It's actually PUR curve....

So you're right then. No spectrum sensitivity thingy in PAR,
as long as it's between 400-700 nm, one photon, one vote.

Thanks!

 

[SuperColey1]

Not sure if you're being sarcastic there Can you confirm because I am learning all the time too and want to correct myself if needed. More important for me to correct anything in my knowledge that is incorrect than to continue assuming something else

I think what I am saying (and I am not sure myself) is that maybe the spectrum can dictate the PUR in that there can be more light outside the usable range from one spectrum versus another. Does that mean though that the PAR will be the same?

I'm not sure we could really address the spectrum issue in that they all just say 'full spectrum' which I assume is why most use the K rating as an indicator of what sort of range the light will be at.

AC

 

[SuperColey1]

OK after looking at the article linked to below I'm not sure whether I am right or wrong.

PAR does measure all intensities from 0 to infinity?
PUR measures just the usable range.

On the link it shows that the with the Solaris (using Philips Luxeon 3W LEDs) PUR is approx 87% of the PAR whereas an XM lamp is circa 78%

That would suggest that when we measure PAR one person with X brand of lamp compared to another person with a different lamp could have similar PAR yet much less PUR.

It could also mean that someone using X lamp has lower PAR yet more is the PUR range.

I remember a thread on here a while back where someone measured 2 named brand tubes wand one was 130% PAr compared to another. It now occurs to me that maybe they could still have the same PUR!!!

I guess what I am getting at is that spectrum indeed could well play a part here. One lamp maybe higher PAR but not giving as much % in the usable range if you see what I mean.

Link:
http://www.advancedaquarist.com/2006/8/review2


AC

 

[nipat]

Not sure if you're being sarcastic there Can you confirm because I am learning all the time too and want to correct myself if needed. More important for me to correct anything in my knowledge that is incorrect than to continue assuming something else ---

I'm not being sarcastic.

 

[nipat]

---

I'm not sure we could really address the spectrum issue in that they all just say 'full spectrum' which I assume is why most use the K rating as an indicator of what sort of range the light will be at.

AC

But the K rating still doesn't tell me a 10000K bulb is biased to blue or pink.

OK after looking at the article linked to below I'm not sure whether I am right or wrong.

PAR does measure all intensities from 0 to infinity?

I don't know too.

PUR measures just the usable range.

On the link it shows that the with the Solaris (using Philips Luxeon 3W LEDs) PUR is approx 87% of the PAR whereas an XM lamp is circa 78%

That would suggest that when we measure PAR one person with X brand of lamp compared to another person with a different lamp could have similar PAR yet much less PUR.

It could also mean that someone using X lamp has lower PAR yet more is the PUR range.

I remember a thread on here a while back where someone measured 2 named brand tubes wand one was 130% PAr compared to another. It now occurs to me that maybe they could still have the same PUR!!!

I guess what I am getting at is that spectrum indeed could well play a part here. One lamp maybe higher PAR but not giving as much % in the usable range if you see what I mean.

Link:
http://www.advancedaquarist.com/2006/8/review2

I agree that PUR has something to do with spectrum.
But isn't PUR varied between species of plants so it seems no point to worry about it
unless you know the PUR of the plants you're growing ?

 

[SuperColey1]

I agree that PUR has something to do with spectrum.
But isn't PUR varied between species of plants so it seems no point to worry about it
unless you know the PUR of the plants you're growing ?

PUr is a fixed light range as I understand it rahter than a variable dependent upon the lifeform.

AFAIK PUR is the 400-700 ish range and all life uses light between this range. Outside of this range are dangerous light ranges like UV etc.

However as you infer I would guess some plants prefer light from a certain section within this range and I guess that this may vary. Not sure they like anything atall outside of the PUR range thoug

AC

 

[nipat]

PUr is a fixed light range as I understand it rahter than a variable dependent upon the lifeform.

AFAIK PUR is the 400-700 ish range and all life uses light between this range. Outside of this range are dangerous light ranges like UV etc.

However as you infer I would guess some plants prefer light from a certain section within this range and I guess that this may vary. Not sure they like anything atall outside of the PUR range thoug

AC

Now I'm confused. Isn't PAR a range of 400-700 nm while PUR is the preferred wavelengths (or sections)
within PAR that is varied between plant/organism species?

http://www.plantedtank.net/forums/lighting/78632-par-vs-pur-measurement-light-efficency.html




[The following is a side note explaining why I misunderstood that PAR had spectral preference]
Before, this graph made me think PAR has something to do with spectrum.
But although they call it "typical PAR action spectrum", it's not PAR. It's just a spectral sensitivity of types of chlorophyll.

PAR has no wavelength preferences. Just simply counting photon between 400-700nm.
http://www.apogeeinstruments.com/quantum/spectralresponse.html
http://reefkeeping.com/issues/2006-04/sj/index.php (in Units for Photosynthesis Measurements)

For the purpose of photosynthesis, light is termed Photosynthetically Available Radiation (PAR). This radiation's range is identical to what humans can see in the 400-700 nm range, but each photon is treated uniformly in this measurement (unlike the photometric measurement, which weights the photons according to how the human eye sees them).

 

[SuperColey1]

The last statement MAY explain the misunderstanding. They call it 'P available R' whereas I understand PAR to mean 'P active R'.

Active would suggest that it is all ranges whether useful or not. Thats just interpretation though so could be wrong.

I am going by the first chart on the link I gave where it shows from 0 upwards, not starting at 400. however reading on I see that he says what you say r.e. what PUR is, in that for his experiment he is looking for specific ranges of 400-550 and 620-700 which are the ones he says are good for his subjects photosynthesis.

To do the charts he uses a spectrometer to measure the 400 - 700 range.

Maybe someone can confirm if PAR actually measures all ranges including those outside of 400-700 or not?

I agree with you now on PUR after reading properly. lol

AC

 

[Cyclesafe]

I am more than a little intimidated by this discussion, but with equal magnitude impressed with AC's DIY result. My take away is that one Ecoxotic Panorama 8000K Module might work on a 1-2' long low-light tank, but we still don't know the amount of usable light it provides. Also, the company's stated incremental benefits of low heat, bulb longevity, and shimmering effect are likely over-stated, but I think that these specifc claims are still within the bounds of acceptable commercial puffery.

If there is not significantly less heat into the tank, then I'm not sure if the other benefits listed are enough for me to switch out a perfectly good CF fixture. OTOH, I remain intrigued and would be interested in hearing the experience of others.

An adaptation of AC's DIY effort for my wood canopy is another possiblity, but with no heat benefit.....