DIY LEDs - The write-up

[jerryz]

I remember when T5s came into the hobby and the comments ran the same arc. Started out that they weren't adequate, then they went to well probably adequate but do they provide the color pop. lol the whole time our corals keep growing and the hobby keeps advancing.

 

[der_wille_zur_macht]

Santoki,

In general, I agree - it's pretty clear that if anything, it's easy to build an LED fixture that's TOO intense. The differences between a Q4 XR-E and R5 XP-G can make this much easier - if someone was to "copy" your fixture but use XP-Gs, they'd certainly burn away all the corals in their tank.

That said, the one advantage "better" LEDs can still provide IMHO is increased efficiency. You can run the same number of LEDs at a lower current and have less power used, and less heat generated. Depending on your tank's circumstances, power consumption and heat generation might or might not be important, making the advantage greater or smaller for different people.

Jerry, to add to your point, there have been some people alarmed that corals "changed" colors under LEDs, and immediately assuming that the LEDs are somehow bad for the corals because of this. It's easy to forget that corals will almost certainly change colors if you switch from MH to T5, or from one MH lamp to another - again, as Santoki pointed out, there's a ton of room for subjectivity here.

 

[Santoki]

Santoki,
That said, the one advantage "better" LEDs can still provide IMHO is increased efficiency. You can run the same number of LEDs at a lower current and have less power used, and less heat generated. Depending on your tank's circumstances, power consumption and heat generation might or might not be important, making the advantage greater or smaller for different people.

totally agree.
However, I think the majority are missing this point, as I don't see general emitter counts decreasing with the newer emitters. If anything it seems like it is increasing.
People seem to forget that Soundwave's build "only" employed 48 LEDs total for his original build.
-R

 

[der_wille_zur_macht]

People seem to forget that Soundwave's build "only" employed 48 LEDs total for his original build.
-R

Without optics, too! And he's posted plenty of good SPS growth shots.

 

[TheFishMan65]

Any one remember what he was finally running his current at? I think he planned for 1000ma, but I also think he turned it down.

 

[der_wille_zur_macht]

700mA on whites, 1000mA on blues, non-dimmable, according to the first post.

 

[CJO]

I finally have everything here or on order and intend to try to get started in the next few days. I have a Cora-Life Coralight 36" fixture with two built-in fans, a splash shield and the internals taken out for the housing. I'm using a 35" long x 5.375" wide x 1" high heatsink, 24 Cree XR-E Royal Blues and 12 Cree XP-G Cool White LEDs.

I have three Mean Well 60-48D drivers, but would prefer to use only two of them- one for the blues and one for the whites. I plan on running two strings of 12 blues in parallel with a 1A quick-blow fuse on each and binning the LEDs so that the forward voltages are the same. The driver would be running at 1.4 amps, which would result in 700mA per string. I will dim them with the Neptune Apex's variable 0-10V output. Does this sound right? Is there anything I'm missing?

Also, the XP-G's are rated at 1.5 amps (rather than the 1A for the XP-E's). Is there any reason not to run them close to this, assuming the PAR value is not too high?

Thanks,
CJ

 

[TheFishMan65]

The only reason not to run them that high is the heat. I have not read of anyone trying it so don't know if it will work. Remember that LED life is related to how hot you run them. As long as you can keep them cool you should be OK. Are you running with lenses, what is your tank size? The only other issue might be spotlighting with the whites, but there has been discussion on that so I assume you understand those issues.

 

[CJO]

It's a pretty large heatsink for the number of LED's, plus I have active cooling. The only question is how well the fans will vent them since it is in an enclosure. If it gets too hot, I'll look into what else can be done- perhaps changing out the two small 60mm fans for a single 120mm and/or lowering the current if there is plenty of PAR. I'm not running any optics for the start. I want to see how it does without them and then look into ordering some if needed. It's a 65 gallon tank (36"x21"x21").

Thanks!
CJ

 

[sahin]

The problem with these types of comparisons is that there are many factors outside of lighting which have impacts on color. Water chemistry for one, I feel plays a much larger role in coral coloration than lighting.
Also, coral color preferences are subjective, which makes it hard to compare one to another.
Personally, I feel that there is too much focus in getting enough light into the tank. I think there is still a general fear that one may not have enough LEDs for their tank size, or that the LEDs are not intense enough, driving many to focus on the latest greatest emitters, higher numbers, etc...
Just a reminder, my build uses Q4 CW XR-Es, which is outdated technology by this thread's standards. I wouldn't say I have any problems with intensity, nor do I wish it to be any more than it currently is. If anything, I am seeing borderline bleaching in my Yongei colony branches where two pendents' output overlaps, which I attribute to too much intensity. Also, that is the only coral in my display which hasn't really grown.
I think great coral colors can be had with these LEDs, as with T5 or MH. However, I think the focus needs to be more on husbandry and less on the actual light.
-R

I agree with what you say. I am looking to see overall do LED's allow us to get the colours achievable with T5's (water chemistry and other parameters aside)?

I actually have 16 Cree RB's @ 700mA and 150w Phoenix 14K halide over my 28G nanocube. The LED's run the perimeter of the halide. This is perfect as the side/back/front are now lit up as well if not better than the centre.

Here is my tanks thread:
http://www.reefcentral.com/forums/showthread.php?t=1830987

The colours have improved since I posted those photos, but I am still wondering if LED's alone can produce colours as seen under T5's.

Please post photos of your tank/closeup coral shots.

 

[der_wille_zur_macht]

It's a pretty large heatsink for the number of LED's, plus I have active cooling. The only question is how well the fans will vent them since it is in an enclosure.

Are the fans just creating air movement inside the enclosure, or actually pushing/pulling air in/out of the enclosure? The latter is definitely highly preferable.

 

[pheinzig]

a shameless bump I know.
But with all the talk of color growth ect, Im thinking my bottom post on the last page might have gotten missed.

Been at it for a couple hours now.....
cant find a good vendor for variable power supplies.

I'm using the ever popular Mean well series "D" drivers, so I need 0-10v variable power supply.
I would like to find something that can dial 0-9v to allow for inaccurate equipment(i.e. setting it at 9v doesn't mean its exactly 9v, it might actually be pumping out 9.4v).

Since you can tune the driver to around 950+ MA at 9v, ill be golden since I don't want to go much past 700ma.I would really like one that has a wide range of variability.But Ill even consider something more basic like this:
http://www.mpja.com/prodinfo.asp?number=9902+PS
the problem with this one is it goes up to 12v. I don't want an accidental over power. Any suggestions?

PS,
as for color growth, my understanding was that the color really pops out under the blues.
This was one of my main reasons for wanting to switch to LED.
I intend to have a dimmable system so when I want to show people some amazing coral, I can dimm the white, and up the blue :eek1:

 

[adova]

Well, if you were ever thinking of getting a controller for your tank, the Reefkeeper lite and Elite have an Advanced Lighting Control (ALC) module that does 0-10v spot on. Probably more $ than most people want to spend on an LED solution, but then you get the other benefits as well...

Otherwise, just get a 9v straight from radio shack and a potentiometer to dial it down...

 

[der_wille_zur_macht]

a shameless bump I know.
But with all the talk of color growth ect, Im thinking my bottom post on the last page might have gotten missed.

Do you need an off the shelf solution or would DIY be more desirable?

PS,
as for color growth, my understanding was that the color really pops out under the blues.
This was one of my main reasons for wanting to switch to LED.
I intend to have a dimmable system so when I want to show people some amazing coral, I can dimm the white, and up the blue :eek1:

Most corals do "pop" really well under royal blues, but it strikes me that the subject of longterm color changes is valid, as well. In other words, if I have a really nice brightly-colored coral under MH, and I put it in an LED tank, it might look good on day one, but is it going to turn brown a month later?

 

[pheinzig]

Do you need an off the shelf solution or would DIY be more desirable?




Most corals do "pop" really well under royal blues, but it strikes me that the subject of longterm color changes is valid, as well. In other words, if I have a really nice brightly-colored coral under MH, and I put it in an LED tank, it might look good on day one, but is it going to turn brown a month later?

1. Off the shelf simplifies it.
But honestly, if my understanding of electronics has come this far, then a DIY is also feasable at this juncture. I would like to consider tackling it!

The previous post mentioned a straight 9v power supply with a pot. I think that's reasonable. Honestly, probably better since you can have more fine tuning with a pot(at least I think you can). Off the shelf regulators Ive seen have onle a set limited number of currents. i.e 1.5/3/7.5/9/12.

With a pot wouldn't I be able to reach everything in between? I personally like that idea MUCH MUCH better! So ill take advice on both, but if a 9v w/pot is really as simple as it sounds, Ill opt for that

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2. Ok I see what you mean. Long term effects.The best Ive seen is before and after shots 1 year later. And everything looked fine to me.

 

[der_wille_zur_macht]

The easiest thing to do is probably to get a regulated 9v wall wart and a pot, and use them to send a 0 - 9v signal to the driver. This isn't exactly a "correct" implementation because you'll never hit the 10v max the driver can take, but you can adjust the internal current trimpot such that your 9v signal translates to your target max current.

 

[CJO]

Are the fans just creating air movement inside the enclosure, or actually pushing/pulling air in/out of the enclosure? The latter is definitely highly preferable.

The latter- there are two fans on one side of the enclosure pushing in air and two vents on the other side to exhaust it.

CJ

 

[pheinzig]

The easiest thing to do is probably to get a regulated 9v wall wart and a pot, and use them to send a 0 - 9v signal to the driver. This isn't exactly a "correct" implementation because you'll never hit the 10v max the driver can take, but you can adjust the internal current trimpot such that your 9v signal translates to your target max current.

Sounds simple enough:
1. go get a 9v wall wart.
2. cut the output line and splice the positive to the positive on the potentiometer, and the neg to the neg on the pot.
3. run the out put of the pot to the meanwell driver. Viola! you have a variable power supply that is capable for going from 0-9v.
4. adjust the Mean Well driver to put out max capacity at 9v!

I can do that. From there its a matter of making a nice control box that has 2 pots in it. Ill label one white, one blue.
THX!



* can I run 2 pots of the same 9v wall wart? I think yes, since the amperage isnt going ot matter a whole lot.
But I just wanted to ask.
I imagine all I would need is a "Y".

 

[adova]

My problem was finding a POT that would work with the wart - radio shack didn't have anything...

 

[pheinzig]

My problem was finding a POT that would work with the wart - radio shack didn't have anything...

What would determine incompatible?
I thought pots had a pos/neg input/output.
After that isnt it just a matter of finding one that can do around 9v?
Even one capable of doing off of 12v should still be ok right?