PDA

View Full Version : L.E.D Questions


SleepyPirate
06-24-2011, 11:14 PM
Iv noticed people selling off there metal halide lights for L.E.D lights anyone have any information on them?

HL649
06-24-2011, 11:48 PM
I recently set up a 2nd tank and went with LED lights. In my opinion they are nice. They give out nice light, they shimmer, intensity is dimmable, and mine have a real nice timer built into the stock controller. Less power, more light, and less heat.

eli@fijireefrock.com
06-25-2011, 01:29 AM
I love the look and the extension on my corals under the LED lighting.using half the power with a longer life on the system there is actually nothing that i could think of that is bad.
If you like you could come by and see for yourself as i have half of my reef lit by LED and the other half with a 400W metal halide.

naesco
06-25-2011, 02:36 AM
I have had LED on my tank for over one year. I agree with all of the above.
They use much less electricity, produce very little heat and only need replacement every five years. A slam dunk decision in my opinion

intarsiabox
06-25-2011, 03:06 AM
Fortunatly LEDs are slowly coming down in price. When I compared the cost of even the cheap Maxspect LED's (not even with the cree lamps) to a Hamilton MH+T5+Moonlight set up last year for a 4' tank it would take 5-6 years of bulb changes and the cost of the fixture to add up to the price of an LED set up. Now there are some mid range models that aren't as badly priced. Even only 1-2 years ago it was either super expensive high-end or very expensive low-end units but now with a lot more manufacturers you can get a half decent fixture for the price of a good MH+T5 combo if you shop around.

eli@fijireefrock.com
06-25-2011, 03:41 AM
Fortunatly LEDs are slowly coming down in price. When I compared the cost of even the cheap Maxspect LED's (not even with the cree lamps) to a Hamilton MH+T5+Moonlight set up last year for a 4' tank it would take 5-6 years of bulb changes and the cost of the fixture to add up to the price of an LED set up. Now there are some mid range models that aren't as badly priced. Even only 1-2 years ago it was either super expensive high-end or very expensive low-end units but now with a lot more manufacturers you can get a half decent fixture for the price of a good MH+T5 combo if you shop around.

I will have to agree on the above noted.
That is why i went with a DIY system only recommend it if you have time and the know how for DIY

Magma
06-25-2011, 05:54 PM
only need replacement every five years.


Why every 5 years? I have been looking into LED lights and I have read from some sites, 3 years, some say 5, others says when they burn out.

My understanding from using LED's with sign installations for commercial businesses is that LED's wont technically "burn" out but they do fade over time, most LED's I have seen are rated for 30-50,000 hrs of burn time which is well over 3 years of light if ran 24hrs a day, 7 days a week. The spectrum of the LED wont change either due to how they are made, if it is made to produce blue it can only ever produce that colour. But white LED's are made with phosphurs which turn a blue led into a white one, so the white will change to become blue over time but that doesn't seem to make me want to replace the whole unit every 5 years.


Just curious as to what everyone else thinks on replacement time?

chandigz
06-26-2011, 12:46 AM
I believe the 3 year(30000 hr life, generic and cheap or lower end leds) or 5 year(50000 hr life, Cree leds and other high end leds) rating is based on the fact that at that point they will only be producing 70% of the original output not because of colour shift. Led's don't use phosphores and therefore should not go thru a colour shift like halides/flouescents. Replacement times depend on the quality of leds,heatsinks used, hours per day, types of drivers( constant/variable current drivers, or voltaged regulated drivers on low end and cheap chinese units), and how high they are driven. The higher quality units usually have replaceable or customizable leds/led panels.

Magma
06-26-2011, 01:13 AM
The white leds can only be made 1 of 2 ways though, either you use one that emitts a red yellow and blue and mix them or you use a blue with phosphor material to convert the wave. So with that respect I understand why you would change the white ones. But I dont believe that the drivers from china would really be that much worse I mean they are all probably made in China to start with.

Only reason I say that is I installed a sign about 6 or 7 years ago now with over 500 red LED's in it, it has a step down transformer on it and regulates the voltage and current passing through the strips of LED's and those have not faded or needed any upkeep since we put the sign up. All the parts on them said "made in china" and most of it came from a local electrical wholesaler.

So to me having seen long term how those LED reacts im just wondering if the "fade" will really be that noticeable when your only running them for 10-12 hours a day.

That being said though these were LED strips with 2-5 LED's per strip not singles. Maybe time will truly tell us...

chandigz
06-26-2011, 02:02 AM
I didn't mean all made in china are bad or anything like that. What I meant is that some of the cheap chinese generic lights that I have seen use cheap voltage regulated transformers not constant/variable current drivers and thin aluminum plate instead of proper heatsinks. You get what you pay for. Constant current/variable current drivers can really make a difference when it comes to high power leds. The current technology in high power leds is changing so fast and you can hardly compare it to led technology 5 years ago. Sort of like comparing lemons to limes. They're similar but different. The sign you have probably uses low power leds which basicaly all use voltage regulated transformers with resistors.

You might not notice a big difference in light output over five years but i'm sure your high light corals would notice a 30% drop in output. A 30% loss of output could really affect coral growth. I actually thought 30% loss was pretty high to wait for to change a bulb/bulbs. If it wasn't for my coral I wouldn't replace my halides/florescents for 8 or more years like my brother. His tank still looks bright and colour is not too bad i guess. Most of us replace any lights mostly for loss of output first and colour shift secondly. So I guess replacing the leds comes down to wether you want "great" coral growth or just "keep" high light coral, grow lower light coral or fish

Magma
06-26-2011, 02:45 AM
Ok poorly made drivers makes more sense than Chinese ones. I also understand what you mean from changing the bulbs after they start to loose colour for looks and for growing reasons, I guess it boils down to each person needs for what they want to grow and how often you want to do the upkeep.

Im wondering now that you mentioned the lower power leds if you cant just use more of them instead of the higher intensity ones? So instead of 1W leds you grab 2 smaller ones or 4 depending on the amperage they are and use those instead? Again it might depend on the tank you want to put them over..

chandigz
06-26-2011, 03:58 AM
Low power leds have proven to be virtually ineffective for growing coral. They are also a lot less efficient. The new high power leds produce a lot more light per watt then low power led. You also don't get the penitration with low power led. The intensity drops off so fast passing thru water. A local store was selling led light strips with 200 low power leds in each tube Because he figured leds are leds and I know someone that got conned into 6 of these (1200 leds) on a 65 gallon 22" deep tank and they were totally useless for keeping coral growing or alive. 1 Watt leds? They are outdated when it comes to reef lighting. They proved ineffective except for shallow tanks. You want The newest generation 3 watt leds. Most decent fixtures use three watt leds driven at 700ma for a wattage of 2.5 watts. They drive them below their max opperating range to make them last longer because of don't run as hot. Everyone thinks leds don't get hot, they do. Thats why they need a proper heatsink/cooling system. They don't emit heat as they don't produce infrared radiation(heat is not projected into the tank). The more efficient the led the less thermal resistance so they don't get as hot. Just over a year and a half ago 107 lm/w was top of the line and now the newest Crees can produce over 160 lm/w and will run at a maximum drive current of 3000ma. In Cree's research they have actually broken the 200 lm/w barrier that was once thought impossible. You here Cree a lot because they are the leaders in led technology and have some of the highest standards. There are others but some say Cree are the best.