LED help is needed

[Jarred1]

Hey everyone,

I am planning on making an LED actinic supplement bar for my tank and just wanted to know a few things before I start. I am going to buy a kit from rapidled and the kit comes with xt-e leds, how many watts are those? The driver is a Mean Well LPC-35-700 constant current driver and will be driving 9 of the xt e leds. Any help is greatly appreciated.

Jarred

[03LightningSVT]

The xt-e's are 3 watt. I believe that driver will light a string of up to 12 Cree royal blue xt-e led's.

[Jarred1]

When I first built a LED light there was cree xr-e leds is there any difference between the xre and xte?

[unkel j]

From Rapid-


"Mean Well LPC-35-700 constant current driver

$16.00

For driving 1 string of 3-14 CREE XP-/XT- LEDs in series. Can also be used for XP-G and our red LEDs."

[pwreef]

Don't skimp and buy a dimmable driver with as many LEDs are it will fit - 14. 700mA driver will only drive them at 1/2 of their max current - 1.5A which incidentially makes them a 5W max LED. If you are getting a proper heatsink, which you should get the 1050mA driver for these. Good luck!

[Jarred1]

Wait a minute, so the non dimmable drivers won't drive them at their full potential? Will 9x3w royal blue leds show even with 2x150w metal halide lights on?

[Dave Thebrewguy]

Wait a minute, so the non dimmable drivers won't drive them at their full potential? Will 9x3w royal blue leds show even with 2x150w metal halide lights on?

9 Royal blues at 700mA will add some 450nm light to the tank but I doubt you will notice much of a visible difference.
The LPC-35-700 is a non-dimmable constant current driver that puts out a fixed 700mA at anywhere from 9 to 48v. The Cree XT-E can handle up to 1500mA and will have a fV of ~3.33V, this is 5 watts. Of course, running at full power has a reputation for shortening the life expectancy of the emitter.
Since the LPC-35-700 puts out a fixed 700mA, that is the current that will drive your LEDs. At 700mA the XT-E will have a fV around 3.1V which is around 2.25 watts each. Nine LEDs at 700mA would give you around 20 watts total.
PWReef's comments about using a LPC-60-1050 and the maximum number of emitters were good advice. At 1050mA the XT-E will have a fV around 3.2V which would give you around 3.35 watts each. Nine LEDs would give you a total of around 30 watts. Either driver is capable of running up to 14 LEDs (15 may even be possible but that's pushing it) and by using more emitters you can increase the output even more. Fourteen XT-Es at 700mA would be around 31 watts and at 1050mA you'd get almost 48 watts.
So there you have it, using the next driver up and a few more LEDs will cost you about 50% more to start but will give you almost 2.5 times as much light. You didn't mention the size or surface area of your tank but I am confident you'll notice the difference.
BTW, a little 420nm might help as well, If you decide to stick with the LPC-35-700 you could always mix in a couple of the violet LEDS, maybe 11RB/3Vi or so. This won't work on the 1050 driver, the Violet LEDs can only run at up to 700mA but I've heard they can be run at their max without damage. At 417nm these are Violet, Rapid calls them UV but they are not UV (which, IMO, doesn't inspire confidence in the vendor, but YMMV).

[Subw00er]

Dave, I might challenge you on some of that info. On paper it makes perfect sense, but in practice, I've seen some things that matter.

Keep in mind though that after about 75-80%, I dont notice big increases in intensity with the crees - the brightness curve is not linear. I've built about 5 setups now. I have used the 48d and the black dimming nano drivers (http://www.rapidled.com/0-10v-dimmable-nano-driver-with-potentiometer/ ). I actually like the nano drivers because they are dead easy to install, the pot is a great feature if you dont have a control system, and to be honest in real world testing I dont see huge improvements in brightness over a meanwell driver. The nano can support up to 10 leds.

The thing to consider is that some of the leds are still at 1amp max, so if you did install a meanwell on a mixed led setup, you might not be able to tune for 1.5amp anyway or you'd blow the smalelr crees. So if you consider the difference in intensity between a 1amp and a .7, there's is little to nothing in the way of a brightness increase. I actually run my main light at 80% because above that all I get extra is heat.

On top of that the leds will run cooler and last longer at .7amp!

9 royal blue on a 700ma will be REALLY bright!! I've done it!

Here is a link to one of my build threads.. halfway down is the led part. http://cdmas.org/forums/index.php?topic=10176.msg87089

[Dave Thebrewguy]

Dave, I might challenge you on some of that info. On paper it makes perfect sense, but in practice, I've seen some things that matter.Challenge all you want :)

Keep in mind though that after about 75-80%, I dont notice big increases in intensity with the crees - the brightness curve is not linear.
I agree, but we're not talking about going above 80%. I posted info that covered running at 40% and 60%, well within the range where you have to admit that there is a noticable difference.
I've built about 5 setups now. I have used the 48d and the black dimming nano drivers (http://www.rapidled.com/0-10v-dimmable-nano-driver-with-potentiometer/ ). I actually like the nano drivers because they are dead easy to install, the pot is a great feature if you dont have a control system, and to be honest in real world testing I dont see huge improvements in brightness over a meanwell driver. The nano can support up to 10 leds.
You'll have to challenge someone else with all this. I didn't bring up any drivers, I just added some figures to help compare the drivers that had already been mentioned. I considered adding the ELN series (I have a 48P myself, but I'm not impressed with it and it will be replaced soon with LDD series drivers) but I didn't want to confuse what shoud be a simple "actinic suppliment strip."
The thing to consider is that some of the leds are still at 1amp max, so if you did install a meanwell on a mixed led setup, you might not be able to tune for 1.5amp anyway or you'd blow the smalelr crees.
The OP was specific about using XT-Es, and as above, this sounds like a simple "actinic suppliment strip" so I didn't see a need to confuse anyone with discussions about any other Cree product. I can't think of any other Cree product that belongs in this type of project, the only thing I'd add is a few Violet emitters and you'll notice that I did discuss the maximum current.
So if you consider the difference in intensity between a 1amp and a .7, there's is little to nothing in the way of a brightness increase. I actually run my main light at 80% because above that all I get extra is heat.
I think we covered most of this, we are looking at current levels that work out to roughly 40% and 60%, we are well under 80%.

On top of that the leds will run cooler and last longer at .7amp! I think I covered lifespan issues when I mentioned the XT-E's max ratings and pointed out that this would impact longevity.

9 royal blue on a 700ma will be REALLY bright!! I've done it! "Bright" is relative, the question was not "will it be bright," but "Will 9x3w royal blue leds show even with 2x150w metal halide lights on?" I wouldn't expect it to make a huge difference, it will add light but it won't be dramatic. I'm sitting 10 feet from a tank with a string of 5 XT-E RB and 5 Luxeon ES RB at 960mA, they suppliment 2x 54w T5 Actinic White, 2x 54w T5 Actinic and a string of 10 Luxeon ES NW at 700mA (on the ELN). My other lighting has less output than a pair of 150w MH and with 10 LEDs at 960mA the difference is not that big.

Here is a link to one of my build threads.. halfway down is the led part. http://cdmas.org/forums/index.php?topic=10176.msg87089Thanks for the link. I'll try to take a look later. I really only came in from the garage for a few minutes and I've got to get back to my project, the third generation LED build for my 90 gal.

[Jarred1]

If you guys were to make your own accent light what would be your list of stuff to get? I don't need it to be dimmable. The tank is a 40 breeder with 2x150w halides with Phoenix bulbs.

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[GrowingTheReef]

Well in my own personal opinion I would go all LED. Ive seen side by side tanks (One was metal halide and the other was LED) and the Led tank seemed brighter, more shimmer, and the coral seemed to pop more and look healthier. Either way metal halide AND Led is a good choice.
Maybe go with the "Mean Well ELN-60-48D dimmable driver" yes it does cost more and is a dimmable but adding 14 Leds could help and then you can increase/decrease the intensity if you dont like it. I would suggest maybe a mix of Blue AND Royal Blue.
So 4 Blue and 10 Royal blue
Also if you want to give the coral in your tank an extra POP you could add 2-4 UV on that string?
Maybe have 2 UV, 2 Blue, 10 Royal Blue?

Just throwing out suggestions,

Nick-

[hllywd]

Wait a minute, so the non dimmable drivers won't drive them at their full potential? Will 9x3w royal blue leds show even with 2x150w metal halide lights on?

IMO the blue will be noticable, even driving the LEDs @700mA. While you may get a little more intensity by driving them harder, it comes at the expense of efficiency, emitter life, and heat. On this specific point, as you have your rig specified, I believe you'll observe a significant blue addition to your 150s.