LED Aquarium Lights vs Metal Halide

 

LED Aquarium Lights vs. Metal Halide;
Yahoo Answers Hall of Shame #8; Can you use LED Lights for planted freshwater or Reef Aquariums?

With correct information resourced from:
*PAR versus PUR; Photosynthetically Useful Radiation
*Aquarium Lighting; Complete Information



I do no know whether to laugh or cry as to two Yahoo answers that were brought to my attention.
Both of these answers could not be more wrong, and sadly the correct answers are no mystery and are not hard to find.
What amplifies the disgust I find with these answers is both are by so-called top contributors and one even claims 15 years experience.

I will give each question and (bad) answer followed by a correction

QUESTION:
Saltwater aquarium LED lights?
I have a 4 ft tank and would like a LED lighting system as an upgrade from t8s. Are there any cheap systems available?

BAD ANSWER (from YA):
No, they are far from cheap, and the technology is still new and not that great. The one time manufacturer of these lights (PFO) was sued and stop making them. Other manufactures are have large problems with computer boards etc. I would avoid them for now , look at t-5s or a good metal halide setup.
15 yrs Reef keeping and this.

CORRECTION:
While cheap is a relative term, when you consider that a LED Light fixture lasts 50,000 hours vs. a T5 that he recommends, as well when you consider a comparable T5 costs as much as 70% of a LED, I would have to even question this subjective part of his answer.
It is also noteworthy that when electricity costs, T5 lamp replacement costs over 50,000 hours, the "High End" LED actually costs much less!!

As to the other part of his answer, I have to ask what planet this guy is on (I mean no disrespect, I just cannot grasp how he can come up with this comment).

While some of the first generation lights (Solaris) were both pricy and not as "good", there is no "one" reef capable LED manufacturer, there are many from AAP/TMC AquaRay, EcoTech Marine, Aqua Illuminations to name a few).

I know for a fact that TMC has had not problems with either its 2nd, 3rd, or now 4th generation (as of 2013).
Ditto for other "High End" LED manufacturers.

As well when you look at all factors; PAR, Lumens Per Watt, Useful Energy (PUR), etc., modern LEDs surpass T5s and even many Metal Halide fixtures (there is tests/evidence to support this too).

What also makes me question the credibility of his answer is that he did not even mention two lighting types that others in the lighting community (not anecdotal aquarium keepers) are aware of; the T2 and SHO Light.
The T2 has a better useful light energy output over the older T5s he promotes.

QUESTION:
im starting a new tropical aquarium and im wondering if these lights are good enough for my fishes health i am planing to stock my tank with live plants as well

BAD ANSWER (from YA):
Generally LEDs are not bright enough for live plants. You can get LED arrays that are bright enough for a small tank, but they are expensive.

For a fish only tank the lights are not as important, you only need them to see the fish better.

CORRECTION

This answer is really bad, where does this person get his information?
Studies that go back to 2006 from outside the anecdotal aquarium hobby/industry (from the horticulture/greenhouse industry where bad results puts them out of business) have no only shown that LED lights can grow plants, but growth is superior to a comparable Kelvin output Metal Halide.

In the picture to the left a 12 watt LED Grow Light similar to the Natural Daylight LED Aquarium Light showed superior growth to a 175 watt full spectrum Metal Halide.

I strongly suggest freshwater plant and reef keepers read this in depth and more importantly well researched and "current" article about aquarium lighting:

Aquarium Lighting; Facts & Information

As well this article should also be read:

PAR versus PUR; Photosynthetically Useful Radiation