L.E.D. vs HALIDE/T5/VHO

[OceanicCorals-Ian-]

Lets use this thread to carry out conversation on test results, opinions, and pro's and con's of L.E.D. lighting for Reef aquariums.

[viperfish]

How many watts per LED bulb is needed to grow SPS coral? Our benchmark for MH or T5 was wattage, how does this compare to LED? Is PAR the only reference available? If someone said they were runnung a 400W 14K MH bulb, you would know it would be awesome for SPS, this doesn't seem to exist in LED. All I hear is brand (mostly Cree) number of bulbs, and number of watts per bulb.

[sphelps]

While LEDs are looking more promising these days my main issue with them is the complexity and reliability. Not too much information out there regarding long term experience and performance. The only fixture that had been out for a while was the solarus but everyone I've heard of using one has had some kind of issue with them relating to either the drivers or LED arrays. In both cases servicing them isn't exactly easy. Other fixtures may be better but their popularity and presence isn't high enough to provide much experience. They also only come with a 1 year warranty which is complete garbage for a fixture that is suppose to last 10 years. Others may disagree but as an engineer in a manufacturing company I know exactly how warranty life is determined and limiting warranty to one year for a such a product is pretty big red flag.

I prefer to spend money on a quality fixture that not only looks good but works all the time. I can't justify spending more up front for a fixture that doesn't look as good, may require constant attention and maintenance and might not even last as long as suggested. Despite the potential energy savings the chance of spending less in the end isn't exactly that good which defeats the purpose IMO.

For now I think the LEDs belong to the DIY electronic guys who can easily fix there own work or build it better with quality parts and those with nano and smaller tanks where the upfront cost is less.

[Ron99]

Originally Posted by medhatreefguy

How many watts per LED bulb is needed to grow SPS coral? Our benchmark for MH or T5 was wattage, how does this compare to LED? Is PAR the only reference available? If someone said they were runnung a 400W 14K MH bulb, you would know it would be awesome for SPS, this doesn't seem to exist in LED. All I hear is brand (mostly Cree) number of bulbs, and number of watts per bulb.

It's not so much a watts per gallon type thing with LEDs as it more depends on how you set up the array. how many LEDs, what optics, how are they spaced. You can set them up to have high or low PAR depending on what you do and your budget.

Originally Posted by sphelps

While LEDs are looking more promising these days my main issue with them is the complexity and reliability. Not too much information out there regarding long term experience and performance. The only fixture that had been out for a while was the solarus but everyone I've heard of using one has had some kind of issue with them relating to either the drivers or LED arrays. In both cases servicing them isn't exactly easy. Other fixtures may be better but their popularity and presence isn't high enough to provide much experience. They also only come with a 1 year warranty which is complete garbage for a fixture that is suppose to last 10 years. Others may disagree but as an engineer in a manufacturing company I know exactly how warranty life is determined and limiting warranty to one year for a such a product is pretty big red flag.

I prefer to spend money on a quality fixture that not only looks good but works all the time. I can't justify spending more up front for a fixture that doesn't look as good, may require constant attention and maintenance and might not even last as long as suggested. Despite the potential energy savings the chance of spending less in the end isn't exactly that good which defeats the purpose IMO.

For now I think the LEDs belong to the DIY electronic guys who can easily fix there own work or build it better with quality parts and those with nano and smaller tanks where the upfront cost is less.

The Solaris fixtures were really poorly built. They had flawed power supplies and no heatsinks so LEDs overheated and burned out. They really weren't designed well. There are some good systems such as the AI ones but also many others that make compromises that reduce output etc.

It's really not hard to design a decent LED system that will be properly cooled and durable. But the costs are still a bit high so if you want a decent LED fixture you have t pay for it. There's no free lunch. Longevity should not be an issue if it is designed well as LEDs are well understood and their lifespan and degradation properties are well known. LEDs have been around since the early 1960s. Ones with enough power for more intense lighting started to appear about 9 or 10 years ago. The technology still has room to grow in terms of output and efficiency etc. so it will only get better.

[sphelps]

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.

[OceanicCorals-Eugene-]

Originally Posted by sphelps

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.