48" LED Array - Up and Running...Mostly

[Canadian]

I apologize in advance for the odd timing of these posts. I had intended to post after work but got caught up with the realtor and was running around all night until going to bed. Now I'm awake in the middle of the night so I thought I'd do something "productive"

First I think you are being overly critical of my light fixture. I would not call it low quality but about a middle of the road one. Sunlight Supply makes good fixtures and these were not much different then the first generation Tek fixtures in terms of lighting output. Slightly better reflectors and active cooling would improve it somewhat but how much do you think that would be? 10%? 20%?

Nope. It's low end. For comparison here is a picture with PAR values for a higher quality T5 fixture. Keep in mind the setup here is still far from ideal given that the fixture doesn't extend the length of tank so keep your eye on the PAR values in the middle of the tank. In this picture you're seeing similar PAR values to your LED fixture with newer lamps and better quality fixture.

Secondly, while the bulbs were old, the only references I could fine say that T5s lose about 10% output over 2 years. The problem for reef tanks is the shift in colour which can lead to undesirable algae etc. But let's say that the degradation was 20% for the sake of argument. So my 300 PAR with the T5s could mean 375 PAR with new bulbs. Still much less than 500 PAR with the LEDs higher above the tank then the T5s were.

Here are PAR values on that same tank one month after the above. This hobbyist measured 20-30% PAR drop WITH ACTIVE COOLING over the course of 6 months. After driving up the fan voltage he was able to cool the fixture enough to keep the drop to 10% over 6 months. So again, old lamps on a low quality fixture (without active cooling) will show 30% + PAR drop over the course of 15 months.

Argue all you want but however you set up my test, new bulbs or not etc. my LEDs handily outperform my T5s. That's all I am claiming.

No arguing. Just trying to ensure there's a reasonable comparison without making hugely inaccurate leaps in assumptions. As shown above, your PAR values are hardly representative of a good T5 setup. And while you claim the comparison is only to your T5s you're trying to report the values as if they're some how representative of T5s by commenting on the relative quality of your fixture and expected drop in PAR of T5 lamps.

Dr. Joshi is an engineer and has been testing all sorts of lights, especially MH, for a long time so I would consider him a good independent reviewer. Here's also a more recent review of a top of the line LED fixture, the AquaIllumination:

http://www.advancedaquarist.com/2007...searchterm=PAR

This one clearly shoes the AI unit outperforming a 250W MH unit. Granted, the MH ballast used may not be top of the line but is probably typical of one used by many people.

I'm well aware of the article. It is quite dated. And again, the comparison is to a 250W 20,000K bulb on a crappy Coralife ballast with an uknown "polished aluminum parabolic reflector". At least you're recognizing that the parameters of the comparison aren't exactly even here.

With respect to who has the biggest PAR; really, who cares. Stoney corals appear to photosaturate between 400 and 500 PAR so having 700 or 1000 PAR is probably pointless other than for bragging rights. I doubt it will do the corals much good.

FWIW, I agree. This was only commented on because Steve got involved in the conversation and has, in the past, made a big deal about the high PAR values he got with his DIY MH setups on his SPS tanks when comparisons to T5s were made. Now that LED PAR values in a typical setup (such as yours) seem to be similar to those of "good" quality T5 setups (see pictures above) he seems to be suggesting those PAR values are now acceptable.

As for longevity and degradation of LEDS, that is fairly well established. While high powered LEDs are fairly new to our hobby they have been around for a decade and are well tested. Low power LEDs have been around far longer then that so the degradation of LEDs is well understood.

With respect to PAR? Please show me the data.

[StirCrazy]

Originally Posted by Canadian

With respect to PAR? Please show me the data.

Andrew, PAR is a function of spectrum and intensity, if you spectrum shifts and your intensity stays the same the PAR changes, if the intensity changes and the spectrum stays the same the PAR changes. with the LED the spectrum is the same through out the life, but like said befor at 50000 hours they will have a 15% decrease in intensity, so the PAR will drop about 15%. With the bulbs we are using now there is a intensity drop and a spectrum cange so the PAR drop can be compounded. I'll see if I can find the article I was reading about it. It comes from the glrow light side of the industry but same concerns, PAR, spectrum, intensity. this industry has had LEDs for over 10 years already, they just didn't have enough punch for coral, but they grew tomatos pretty good aparently.

Steve

[Canadian]

Originally Posted by StirCrazy

Andrew, PAR is a function of spectrum and intensity, if you spectrum shifts and your intensity stays the same the PAR changes, if the intensity changes and the spectrum stays the same the PAR changes. with the LED the spectrum is the same through out the life, but like said befor at 50000 hours they will have a 15% decrease in intensity, so the PAR will drop about 15%. With the bulbs we are using now there is a intensity drop and a spectrum cange so the PAR drop can be compounded. I'll see if I can find the article I was reading about it. It comes from the glrow light side of the industry but same concerns, PAR, spectrum, intensity. this industry has had LEDs for over 10 years already, they just didn't have enough punch for coral, but they grew tomatos pretty good aparently.

Steve

And you're assuming that with whatever installation method you choose for heatsinks and whatever you choose to drive the emitter at there will be negligible thermal damage. Again, and again I say this: theory is great when you don't have real data. We can assume there will be little intensity drop but until we see long term data, especially for the blue emitters that are more prevalent in our hobby, it's just an assumption.

[StirCrazy]

Originally Posted by Canadian

IFWIW, I agree. This was only commented on because Steve got involved in the conversation and has, in the past, made a big deal about the high PAR values he got with his DIY MH setups on his SPS tanks when comparisons to T5s were made. Now that LED PAR values in a typical setup (such as yours) seem to be similar to those of "good" quality T5 setups (see pictures above) he seems to be suggesting those PAR values are now acceptable.

Oh Andrew, I never said they are aceptible or not aceptable, if you go back and look at 99% of my posts on the T5/MH issues it was when people were claiming T5's were more powerfull then MH, and you were one. and if you read carfullyI said many a time that you could grow SPS under a NO bulb as it was done before buy a guy on this board.

your Hi quality T5 set up you showed there, is there any distance referances? and whats the point of taking readings int he air 1/2 way between the reflector and the water? so just under the surface it looks like he has a 575 average in the well lit area. at the bottom about 280ish. the hot spot is a little higher than the numbers but the other areas are lower. (I never realized the hot spot on T5s would be that pronounced) at any rate His number were very comparable with your high end T5 with new bulbs. although we would need measurments of all the reading positions to be sure. so what happens if he adds more LEDs.. nothing, bt if he adds more LEDs to reduce his spacing then adds 40 degree optics his numbers should jump by about 50% from what I have been seeing. if he adds more and then goes 20% optics.. problem is the spacing is so tight on 20% or lower optics it would only be a reasonable cost on a 20 gal tank or less, but man would you pack some punch. I know there are some people trying the the newer bulbs that have about 3 times the output as the ones Ron is using but they don't make that strength in a Royal blue yet so it is only good for the white and they are finding it is to powerfull for any other lighting they try to give it a blue look as it just washes it out. now if you like the icewhite look to your tank, which I tend to.... they might be a awsome bulb to try. I am actualy going to buy a handfull of LEDs and build a tiny cylinder that is about 24" tall but small enough aroundI can lighting it with 2 or 3 LEDs so I can try some different combos on my Ardunio and see what kind of color blending, lenses and PAR values I can get a different depths. just have to clean my shop out first.. which at the way I am goiong should be another 6 months

Steve

[Canadian]

Originally Posted by StirCrazy

Oh Andrew, I never said they are aceptible or not aceptable, if you go back and look at 99% of my posts on the T5/MH issues it was when people were claiming T5's were more powerfull then MH, and you were one. and if you read carfullyI said many a time that you could grow SPS under a NO bulb as it was done before buy a guy on this board.

your Hi quality T5 set up you showed there, is there any distance referances? and whats the point of taking readings int he air 1/2 way between the reflector and the water? so just under the surface it looks like he has a 575 average in the well lit area. at the bottom about 280ish. the hot spot is a little higher than the numbers but the other areas are lower. (I never realized the hot spot on T5s would be that pronounced) at any rate His number were very comparable with your high end T5 with new bulbs. although we would need measurments of all the reading positions to be sure. so what happens if he adds more LEDs.. nothing, bt if he adds more LEDs to reduce his spacing then adds 40 degree optics his numbers should jump by about 50% from what I have been seeing. if he adds more and then goes 20% optics.. problem is the spacing is so tight on 20% or lower optics it would only be a reasonable cost on a 20 gal tank or less, but man would you pack some punch. I know there are some people trying the the newer bulbs that have about 3 times the output as the ones Ron is using but they don't make that strength in a Royal blue yet so it is only good for the white and they are finding it is to powerfull for any other lighting they try to give it a blue look as it just washes it out. now if you like the icewhite look to your tank, which I tend to.... they might be a awsome bulb to try. I am actualy going to buy a handfull of LEDs and build a tiny cylinder that is about 24" tall but small enough aroundI can lighting it with 2 or 3 LEDs so I can try some different combos on my Ardunio and see what kind of color blending, lenses and PAR values I can get a different depths. just have to clean my shop out first.. which at the way I am goiong should be another 6 months

Steve

False. Steve, I never once said that T5 was more powerful than MH. That is patently false. I expect you to go back and provide a quote in context to substantiate that I ever said it was more powerful. All I ever maintained was that T5 was not inferior to MH when you made broad-based statements about inferiority and superiority one way or the other.

The tank pictured above is 5' with a 4' fixture over it. The tank is 60 x 30 x 24. The fixture is roughly 6-7" above the water's surface. The edges of the tank are dim because the fixture does not extend to the edge and because the first 3" or more of a T5 lamp produce significantly less light. Within the 3.5" feet centered below the fixture the PAR is pretty consistent (biased on one side because that's where the fans are).

[Canadian]

And Ron, I apologize for derailing your build thread.

[OceanicCorals-Ian-]

I have a 48" 10 bulb ATI Powermodule on my home tank, the 48" Aqua Illumination module I have seen is brighter than my Powermodule. This of course is just my observation.

On a second note, Ron, you are more than welcome to come over and pull some numbers off my tank. Also, it would be nice to see all of this back and forth discussion on the comparatives between LED and conventional lighting moved to a new thread for this purpose. I was actually just enjoying Ron's build thread as it was.

Ian

[OceanicCorals-Ian-]

I have created a thread specifically for this type of conversation, if everyone is interested maybe the MODS can move the latter half of this vs conversation to the thread I have linked below.

I feel this is detracting from this excellent build thread......

http://www.canreef.com/vbulletin/sho...374#post510374

[Ron99]

Originally Posted by OceanicCorals-Ian-

I have created a thread specifically for this type of conversation, if everyone is interested maybe the MODS can move the latter half of this vs conversation to the thread I have linked below.

I feel this is detracting from this excellent build thread......

http://www.canreef.com/vbulletin/sho...374#post510374

Thanks Ian. Good Idea. Let's move the debate over there.

Originally Posted by Canadian

And Ron, I apologize for derailing your build thread.

No Worries, it's good to discuss it and try to develop real information. I agree that there is lots of manufacturer hype and BS. One reason I built my own array, aside from costs, is that most of the commercial LED lights make compromises of some sort unless you spend big dollars on the high end fixtures.

In any case, let's continue in the other thread.

Originally Posted by Dyspnea

Where did you find most of your reading and research?

nano-reef.com seems to have the most active LED community but more is showing up on reef central now too.