thinking about led upgrades

inkmates

New member
I'm thinking about swapping out my 250w mh for leds and was wondering if 180w of led (1-100w 9500k white and 4-20w blue) would be compariable light output. I'm currently running an off brand 20,000k se bulb. Any input would be great, thanks in advance and happy reefing everyone
 
How deep of a tank? Are you trying to keep SPS? Any unit you have been considering? Can you wait about a year to jump in to LED. What are the dimentions of the tank?
 
if I remember correctly the tank is 28-30" deep 16-18"w/l It will be a diy project and I would like to have a compairable output to the existing 250w mh. personally I think the led technology is ready for or hobby the only inhibiting factor at the moment is cost, color spectrums and output are really good I'll try to remember to post specs on the leds I'm looking at tonight
 
We'd need to know the specs on the specific LEDs you're looking at.

Also, your personal criteria. Many people that do LEDs do so because of potential efficiency savings. Choosing the wrong LED can result in very poor efficiency (even LEDs that look similar can be off by hundreds of percent). But if you don't care about efficiency and are just looking for a cool upgrade, you can pick pretty much any LED as long as you use enough of them.
 
I am in the same boat as you. I want leds and want to replace a single 250w 14k Phoenix. My only concern at this point is depth penetration. Cost of course as well. Every week there seems to be a new fixture coming out. I wish we had a lfs that had a few on display to show the differences. Im sure in time they will replace MH when the price of them come down. I would like to see how bright leds are at 28-30 deep.
 
Now is NOT the time to get into LED's for your main lighting unless you are running a small or nano tank. I've been studying LED technology for 3 years now and have invested in CREE for over 3 years. I also have CREE LR6 LED downlights in my house, which are amazing. The technology is just too expensive right now.

You MUST use the absolute best LED's, to really achieve acceptable PAR rates even in the middle of your tank, 10-12" down. These LED's are expensive and then you are still dealing with how to achieve the best optics to enhance and amplify the light. Wait until the economies of scale catch up and these LED's become much cheaper. At that point, you'll be able to buy an AMAZING LED fixture with a controller that will simluate the lighting at any area in the world, including exact sunrise/sunset, exact spectrum, and randomized clouds and thunderstorms.

I would imagine that someone will write a piece of software that grabs the weather data somewhere in a tropical place, knows the lighting conditions based on season etc... and then the LED controller mimics the weather exactly. I think this is 3-5 years out but it's a great example of how versatile the LED's are and another fine example of how software can make the world a better place.

CREE is still making huge leaps in efficiency and output (lumens per watt). For example, my recessed LR6 lights, which replaced 75w Incandescent lights, use only 12 watts and the color of the light is better and it's even brighter than the 75w bulbs I replaced. I have some installed in a 20 ft high ceiling and they won't have to be changed for another 15-20 years. Each light cost me about $100, so it's going to take a solid 3-5 years to realize a return on my investment, assuming energy costs alone. Now, my time is valuable and gas costs money, so going to Lowes to buy replacement bulbs will probably save me another 1-2k over the lifetime of my LED's. My LED's also give off much less heat, and what heat it does give off, goes above my ceiling into the insulated attic space etc... So in the summer, I'm spending slightly less to compensate for the heat given off etc... So, within the 1.5 years I've had them, they already have chips that give off 30-40% more light and use 10-20% LESS energy. Had I waited, I could have realized a return on my investment in 1-2 year, plus my capital expenditure would have been less, as I can get these for about $75-85 now.

The moral, if you spend 3-5k now, it will take you 5-10 years to pay yourself back, but if you wait 1-2 years, you'll spend 1000-2000 and you'll pay yourself back in 1 year.
 
Now is NOT the time to get into LED's for your main lighting

You bring up a good point. LEDs are developing like any silicone-based technology - IMHO people should evaluate on those same terms. Do I buy an iPod today, or wait until next year when I can get an iPod that's twice as good for half the price? Some people will want to wait, others will want to buy now. Buying LEDs today still means you're getting a great lighting rig at a price that will pay off in the long term, just like buying an iPod today means you get to listen to tunes. If you think people should wait another year or two, why not wait 10 years, when the LEDs available will be 100 times better? At some point, you've got to pull the trigger if you want to be in the game. :)

with a controller that will simluate the lighting at any area in the world, including exact sunrise/sunset, exact spectrum, and randomized clouds and thunderstorms.

Indeed LEDs open up a huge opportunity for those of us who are control freaks. The technology to do what you're talking about is here today, if you're in to DIY. :)
 
Yeah, I see your point but LED's are actually developing much faster than Moore's Law dictates. For that reason, the benefit/performance to cost ratio is growing extremely fast now and will taper off in years to come, so the next 1-2 years will be when the technology begins to hit the sweet spot IMO unless you have a money tree.
 
i'll post up exact specs later tonight if i get the time i'm looking to replace my one 250w metal halide with exactly 5 leds. the 9500k led is rated at 100 watts the other 4 leds will be blue and rated at 20 watts/led. I know first hand how bright the 1 and 3 watt cree leds are and if the 20 watt blue leds are even 5 times brighter than I can't even fathom how much brighter a single 100 watt led could be. This would be my second attempt at an all led lit aquarium The first was lit with 1/4 watt leds (can't remember exactly how many at the moment but it was a bunch for a 2.5g tank) I fried them but it was my fault trying to see exactly how bright they would go without any form of a fail safe. Changeing alot this time around going to use drivers heatsinks and fans and not try to overdrive them. I'll try to post more later acclimating some berghi at the moment. happy reefing everyone
 
heres the link for the 100w white led i'm thinking about
http://cgi.ebay.com/100W-Cool-White...854?pt=LH_DefaultDomain_0&hash=item35ac06978e

and heres the link for the 20w blue leds
http://cgi.ebay.com/20W-Blue-LED-20...752?pt=LH_DefaultDomain_2&hash=item3360b1ea90

theres an couple other types of the 20w size blue leds that i'm also looking into to make sure they emit the correct color wavelength

I'm also looking into aluminum extrusions for the body of the light fixture, I plan on useing individual drivers and heatsinks with 3-4 120mm fans to keep everything running cool. I was also thinking about throwing in a few 5mm blue leds for moon lights.
 
FWIW you'd certainly be able to build a viable fixture with those LEDs but they're roughly 40% the efficiency of the current market-leading LEDs (around 60 lumens/watt for the white, vs. 139 for an R5 XP-G). Plus, I really don't like the concept of a 100w LED chip, especially a less-efficient one - that's a LOT of heat in a very small package. Even with the best heatsink and cooling, you're going to struggle to get a reasonable life out of the thing (IMHO).

The blue LED is a tad high in terms of wavelength, so it'll be more of a washed out "sky blue" color than a true deep blue.
 
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