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

[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

[StirCrazy]

Originally Posted by Canadian

Steve,

. When you were standing on your soap box about MH a few months ago you pounded your chest about getting over 1000 PAR at the surface and 500 on the bottom of the tank. Clearly, the numbers being reported here don't fall in line with what you've purported constitutes adequate PAR for your SPS tanks.
.

yup, I did, and I have no doubt that if Ron put 40 degree optics on his fixture, at 3" he would blow away my MH. and just to add to it my MH were unusaualy high output which was a combanation of the right ballast, my own design for the reflector and good bulbs. in the 25 MH setups I tested the only one that came close was a 400 watt sona agro ballast running iwasaki 6500K bulbs and it was still only slightly over 800.

so I can safly say that a good LED set up such as Ron's will blow any T5 out of the watter, most 150 watt setups, and some of the 250 watt setups. if he would have gone a little tighter spacing which allowed for 40 degree optics with out spotlighting I can say you would be hard to find a MH system that would be a higher output, and it would be pointless to try as at that output level would it realy matter?

Is this because you spent to much on your T5 set up and are haveing buyers regrets Andrew? don't worry I spent close to 10K on lighting in 2 years befor I found something I was happy with myself. now I did recover some of that selling reflectors and reflector material, but still spent way to much on lighting.. thats why the new tank is going to have LED lighting, as it will give me the ability to change color K value on a whim, and also talyor the intensity to what I have in the tank at the moment. if I get a bunch of new frags, I can dial it down and have it increase slowly over a week or two to prevent bleaching. I can have a gradualy sunrise/sunset instead of a two stage on/off. plus the most fun is building the stuff now keeping the tank going.. maybe I should just build systems for people who want a tank but dont want to build it then I could just keep on doing the fun stuff .

Steve

[Canadian]

so I can safly say that a good LED set up such as Ron's will blow any T5 out of the watter, most 150 watt setups, and some of the 250 watt setups.

Please see the picture above of a typical good T5 setup. Would you seriously contend it blows any T5 out of the water? The numbers for the less-than-optimal T5 setup above (I only quickly grabbed those pics because I knew they existed and didn't have to spend a great deal of time searching) are not far off those that Ron is reporting with his fixture.

if he would have gone a little tighter spacing which allowed for 40 degree optics with out spotlighting I can say you would be hard to find a MH system that would be a higher output, and it would be pointless to try as at that output level would it realy matter?

Part of the fun of DIY LED I suppose - trying to optimize spacing with optic angle with height above the water without getting unattractive spotlighting. Even the better manufactured LED fixtures such as AI produce some really ugly spotlighting when suspended at suboptimal heights.

Is this because you spent to much on your T5 set up and are haveing buyers regrets Andrew?

As I've stated several times I actually want to run LEDs and have for well over a year. I'm not anti LED revolution. I'm anti hype based on fuzzy numbers and marketing. I replaced my Giesemann fixture with the ATI I have now and will likely replace the ATI with a couple AI modules in the future. No buyer's remorse. I just want the best of both worlds: efficiency and PAR (not to mention "controlability") in an attractive mass produced product. But I want to make the change based on objective data and not marketing hype.

And this isn't an issue of T5s versus the world. I generally comment on comparison threads when garage "scientists" take it upon themselves to make comparisons as if they're conducting controlled experiments (not that Ron did this or is a "garage scientist" but I didn't want others to try to make comparisons as if the two fixtures were representative examples). The comparison to T5 lighting in this thread is not representative. Had Ron compared his DIY LED fixture to a Coralife MH fixture with a one year old 20,000K MH bulb I would have made similar comments about unfair comparisons. Likewise, I think Sanjay's comparison of the older model AI module to a crappy MH setup with 20,000K lamp is hardly a fair and representative comparison.

I love that you guys are helping develop LED fixtures and ideas for those of us who don't want to go the DIY route. You'll help push manufacturers to make better hobbyist fixtures. And I love that you guys are so enthusiastic about what you're doing. What my concern is, is that some people are getting caught up in the enthusiasm (and blatant marketing hype) and losing site of objectivity. Historically, the same thing happens with new lighting technology coming to the hobby. Reports about T5 longevity and PAR were completely off base for several years until real hard data started to be compiled. The same thing is happening with LEDs to some extent right now. Fortunately, LED lighting is still in it infancy (especially for use in our hobby) and is bound to improve and at the same time some controlled quasi-experimental data will start to emerge.