L.E.D Questions

[Magma]

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]

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]

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]

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.