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Old 04-14-2010, 07:39 PM
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Quote:
Originally Posted by sphelps View Post
Yes I would agree the solaris fixtures where not built that great but there are still very few other fixtures that promise better results. The AI are the better looking fixtures as far as quality goes but to me the module design lacks the style I prefer to see in a fixture for open top tanks and the warranty still suggests a lack of faith in the reliability of the product.

As for LED reliability and lifespan I would strongly disagree. Yes they have been around for a long time but they are new to the hobby and the environment they will be exposed to. They will run hotter and in high humidity and also be exposed to the salty corrosive atmosphere. This will impact the lifespan of the LEDs just like it does for all other types of lights we use. Metal Halides for example are rated for 5 years before a 30% drop in standard applications but over time we have discovered that they only last one year in the hobby application. A similar result will no doubt be discovered with LEDs over time. A friend of mine also pointed out the other day that a lot of cars these days run LED tail lights as manufactures made similar promises about long life and reliability but you still often see multiple burnt out LEDs in taillights on still fairly new vehicles. At least if a regular tail light burns out it's a simple and cheap fix while the LED style simply is not.

An LED by itself is no doubt a reliable light source, however combining multiple arrays into hundreds of LEDs greatly increases the chance of failure and the fix isn't the same as simply changing a bulb.
Its true that MH are rated at 5 years before a 30% drop in standard application, that is if the standard application was not to care about the total PAR values which is often what MH bulbs are used for (parking lots and etc.). The requirement for high PAR alone is what determines how long a MH bulb can be used for in the SW hobby and not so much the environment its been run at. The humidity and salty environment would effect the longevity by a very small amount as the intensity/color shift happens inside the bulb and not outside and a MH bulb is enclosed.

The same would apply for the LEDs except with LEDs heat becomes a great cause of failure on the emitters, most high power LEDs nowadays are rated to run at a constant temperature of 50C to 80C before damage to the emitters occur and most well designed fixtures with proper heatsinks and cooling run the emitters near 40C if not a tad higher. Just for reference the spotlights we carry run at roughly 48-50C without fans and thats 9 bulbs closely package together in a 6" heatsink.

With the car scenario, the LEDs are being put through conditions much more harsh than seen above our reef tanks, they have no heatsinks, no cooling, and have to put up with absorbing the shock and vibrations from the car moving, and I'll agree that we might not get the rated 50,000hrs our of the emitters but it'll be pretty close to it, for a couple simple reasons. LEDs through there lifespan doesnt have much color shift if any at all as theres no gases and no burning seen in the MH bulbs. The intensity will drop but if the emitters are used in the suggested range of specs by the manufacture it should drop to that % claimed by the manufactures.
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