Not Quite Sold on LED Lighting

Bill, i honestly can;t sit here and say leds are better! nor can you say T5's are better! Nor can fishyguy say MH's are better! We've all read are brains too mush on it and made our own judgement! IMO led's will save money in the very not so long term and are maintenance free and very controllable! You like your T5's and they work for you! We all win!

 

Mr. Bill is hitting on a couple very good points (and, points that are reasons I'm an avid DIY LED enthusiast, it's NOT that hard to do lol).

First, I agree that T5HO is here for a long time---- it's just too efficient, user-friendly, predictable, and beautiful (and possibly T2, which seems to be floating around threatening to make an entrance into the reef world, which I think hits the same efficiencies of even top-tier LEDs).



Second, I'm skeptical of high-cost LED arrays. Unlike a T5HO or a halide, they aren't easily repairable. With Halide/T5, if you blow a bulb or a ballast, it's a 5-20 minute fix, tops. If your $800 LED array blows a circuit and you have only blue or white, then what the heck you gonna do if it's out of warranty?????


In any one of my LED arrays, all I have to do is unsolder the blown LED (which isn't that hard), or splice in a new driver of a similar voltage/current capacity.


With most of these new LED arrays, they are using printed circuit boards that make it quite difficult to replace the LED individually---- and they DO sometimes blow. I've had ONE single LED blow on me out of the 60 or so that I am currently using-- over the past two years--- so it can happen.

 

Yes, for the most part exactly. I think that is the main reason. I think there are a few other reasons too though. With halides, I think people tend to use more light than they need, because the step increments are big and upfront costs, really don't change, whether you go with 150, 250 or 400W. And there is blue light, as blue halides just are not very efficient. So, people who run 20000K halides for, whereas blue LEDs tend to be pretty similar to white LEDs in terms of efficiency. Then there is reflectors. A good reflector can make a huge difference, more than doubling PAR from a halide. However, many still stick with spider reflectors, maybe for costs? Or they don't understand how big a difference a reflector makes? Spiders are really complete junk though. So, a lot of people do get away with 1/2 or even 1/3 of the wattage from LEDs compared to halides. I think it is generally some combination of these factors though.

Lumens aren't an absolute measure of visible light, they are a relative measure of perceived visible light. It's not just lumens/watt are limited usefulness. They paint the wrong picture. For example, this thread, which I think is a sister thread for the other, in post 5, states
"However, from table1, we see that the CREE Neutral white, could have almost 6 times the LUX of a CREE royal blue, if the peak output (peak "relative power") was the same."

So why estimate light intensity with our eyes or a LUX meter?

So, basically, theoretically, if you go by lumens, you could think one lighting is many times more efficient than another, when in fact, it is less efficient.

I don't, as it is in-print, not online. I think LED efficiency it is fairly well documented elsewhere though. Remember LEDs, do not produce any UV or IR. So, all output is visible. So, if you find a mw, rating, that will give you the efficiency in terms of PAR, as PAR is all visible light, weighted equally.
Halides, you should be able to find mW ratings, however, halides will waste about 20-30% in the UV and IR spectums, so, you need to reduce the mW rating by about that.

How you drive them does not make that much of a difference. In may in terms of relative output, but not total efficiency. What I mean is, if you have, say 30% total efficiency, that is the LED outputs 30% of the power as visible light, then if driving at a lower wattage, improves the relative output, but 10%, your only changing the total efficiency by 3%. If your speaking in terms of lumens, you may think you are improving the efficiency by more than this, but in mW, or PAR, no way. The problem is lumens are misleading, as they are heavily weighted towards.

You can get a rough idea though from this link. If you add up the PAR for each square from the PAR contour plots, and average them, you should get pretty similar results between lighting sources. the difference is, if you overlay the shape of a typical aquarium, over the plots, there is probably less overlap with the LEDs, so, more is getting into the tank, and you are illuminating it with less wattage.
Feature Article: Quantitative Comparison of Lighting Technologies: Metal Halide, T5 Fluorescent and LED — Advanced Aquarist | Aquarist Magazine and Blog

Okay, I'll have to take a look

Certainly, that could be. I think corals, for the most part though are very capable of photoadaptation. So, with significant acclimation, I think much of that can be overcome. Some corals may not be though, for example, some corals, may not have the ability to regulate pigment production, some LPS may fall into this category for example. In these cases, the spectrum may be more of an issue.

yes, definitely. I think we maybe just have a few very slight different in opinion, for why this is the case.

I'm not quite sure I followed on the PAR readings. However, with a good at about 30" from the bulb, with a 250 Phoenix, I believe that was getting about 400 IIRC. So, not sure, but I may be misunderstanding...

 

Exactly- Thank you.

I'd also like to point out that I'm a "hang it and forget it" enthusiast- buy what you need, put it into place, and turn it on... EOD. I'm more than a little skeptical over the concept of needing to play with dimmers and controllers to keep from frying my livestock, and bleaching or dying corals doesn't seem like a reasonable indicator that you light needs adjusted.

 

Led is more set and forget than t5... After initial set up there is no need to change anything for as long as 10 years... T5 is every 6-9 months...

 

"Up to 10 years" means nothing to me Grim, at least until the technology has been around long enough to prove itself. Anybody can make that claim on most anything. How long is the actual warranty, and how easy/inexpensive is it to fix once the warranty expires?

 

You are both right, but for different reasons.

T5 is more hassle than LEDs since you do have to swap out the bulbs and keep track of how old they are, plus they do shift colors over time (the whites, at least, enough to be noticed with the eye).



However, we have yet to prove that any given LED array can last 5-10 years. Anyone here remember the Solaris debacle? PFO closes up shop, and everyone who owns a Solaris starts having problems with LED strings dying on them, and there is NOBODY to honor the warranty. $1K+, down the toilet.


I'm probably one of the biggest LED enthusiasts on this board, it's the ONLY source of light I use. But I'm not a big fan of pre-manufactured units yet. I want to see longevity, and I just don't know that I can dump $500-1000 on lighting for a 45-90g tank that is "all or nothing". You blow one driver, or lose on string of LEDs, when the warranty is over, there's no way of knowing if you can fix it.


DIY is my favored way. You designed it, you built it, and you can fix it. You don't even need to match the parts up exactly, just find something with similar specs (voltage/current) and you're good to go.

 

Mr. Bill, some on here have had LEDs for 3 years. You yourself stated that you have been using t-5s for 6 years. A 3 year difference isn't such a long time. U would like to see evidence of a quality Led NOT being proven. The biggest downside to led right now is the up front cost. Again, I save 70 bucks a month and paid 400 upfront for a high quality Cree full spectrum dimmable built. Don't worry, I you can change those bulbs you can hit a button to dim or undimm the light. Don't be afraid of something better!

P.s. I seen some LEDs with a 10 year warranty. Most of the drivers 1-2 years. If an led does go, I have neve had one go out but redfish has had one out of Many in 2 years, it's a 3 dollar fix versus a brand new bulb (again). Jut think of the environmental impact if we all got on board!

 

Sorry or the terrible spelling. I phone rocks

 

LOL! Yup, gotta love technology.

What's funny is that I didn't intend for my opinion to become an 8-page technical debate, most of which I already knew. I do, however, understand and appreciate the passion behind each post.

FWIW, I realize that LED is the way of the future; I am watching and following the technology, and when I'm satisfied with the price, performance and reliability of a system that has the features I want (nothing more, nothing less), then I, too, will take the plunge.