Best LED's for refugium?

[AcroSteve]

I have been running the 65w compact fluorescent LOA fixture on my fuge for quite some time. The bulbs never really burn out, but the fixtures sure do.

I have 3 brand new bulbs and hate to not use them, but the ratings on these LOA fixtures makes me think I will just be wasting money a different way.
http://www.amazon.com/Lights-America...7340661&sr=8-4



So, I think I am definitely ready for a change - but what change? I did a very quick look around and did not find many fixtures that use the same bulbs. So should I go with an off the shelf solution, or build my own?

I know I can do the LED thing, what with the excellent leads there are to follow and my experience, but I have not come across many threads that target the light to macro algae growth.

Is anybody doing that?
What are the best bulbs for it?
Optics, or not?

I have a 20gal long for the fuge. I figure one group of six bulbs would be good.


If this has been covered, sorry I have not spent much time searching. Just throw me some links if you don't feel like the discussion. Some of those threads are getting rather long. Where's the summary?


I already have a 24vdc power supply running some controls, I think it might be big enough for one group.

Thanks

[uncleof6]

A 60 watt light bulb will grow macro..... incidentally, just to be a b******, leds are not bulbs: They are LEDs. Light emitting diodes, a big difference

100 watt halogen will grow macro, (a bit of heat though) a couple small T5's, 10000K will grow macro, just about anything will grow macro. Hard to justify, led's to grow macro..... too expensive, and you probably want a separate driver for them.............

Jim

[laverda]

Jim I disagree. True the cost of LEDs is higher but when the amount of elitricity is a fraction of the cost it becomes easy to justify, especially in So CA at $.29 a KWH.
There are a lot of inexpensive LED options if you think outside the box or DIY it. LEDs are showing up in more and more big box stores for less and less. Home Depot and Lowes have some decent units and some crap. Big lots sells a rechargable work light with a magnetic base, charger and 30 LEDs for less then $20.00. I am sure they are not the 3 watt LEDs, but my cheeto does not seem to care at all.

[uncleof6]

Originally Posted by laverda

Jim I disagree. True the cost of LEDs is higher but when the amount of elitricity is a fraction of the cost it becomes easy to Justify especially In So CA at $.29 a KWH.
There are a lot of inexpensive LED options if you think outside the box or DIY it. LEDs are showing up in more and more big box stores for less and less. Home Depot and Lowes have some decent units and some crap. Big lots sells a rechargable work light with a magnetic base, charger and 30 LEDs for less then $20.00. I am sure they are not the 3 watt LEDs, but my cheeto does not seem to care at all.

I agree with you completely. The Chaeto don't care where the light comes from, or how much it cost. $20 qualifies as "anything will grow macro" I can't see the justification for PWM drivers, blah blah blah, to grow macro, perhaps I should have qualified it, but the current rage is not $20 "lights" it is the former.....

Jim

[AcroSteve]

I agree somewhat about the overkill, but if I go DIY LED, it would let me get my feet wet on a small project in case I wanted to tackle a complete setup for my display tank at some point.


However, you say that "just about anything will grow macro", well that may be mostly true, but some bulbs are definitely better suited for it that others. That is what I am looking for input on.

Which of the HD LED's have a light spectrum that is best for cheato growth? I would guess around the 6500k range, but could use some others experiences to draw from.

Conversely, I would like to at least consider an off the shelf fixture or bulb, but do not really live near a large box store where I can check out the selection. Thus the request for input.

[LPSguy]

I'll tag along here, I'm near fuge light selection in my build. Heat and size are big concerns for me in this decision.

[der_wille_zur_macht]

Steve,

Be aware that you're about to tread uncharted territory. There are very few people using LEDs for refugia or ATS so it's not as "nailed down" as using LEDs for main lighting on a reef display tank. There are definitely potential benefits compared to other types of lighting and I think you're right - it can be an easy and "low risk" entry into DIY LEDs.

I don't pretend to be a biologist but the typical approach for refugium lighting is to use warmer light than on a display tank. The typical display tank build is an "even" mix of "cool white" and "royal blue" LEDs. The cool whites are cool in lighting industry terms, but rather warm from the perspective of the reef hobby (typically around 6.5kk - 8kk in the bins we get). Still, there are warmer LEDs that more closely approximate the typical refugium lighting configuration - most white HP LEDs are available in a neutral or warm version, too.

Right now, the "best" white HP LED is the Cree XP-G. It has high efficiency and a relatively large viewing angle, which we probably want in a refugium light rig.

For specific reference, here is a link. Cutter's website is a mess but they have the product:

http://www.cutter.com.au/products.php?cat=Cree+XPG

Scroll down to the menus just below this image, where it says "Cree Xlamp XPG Led:"



They have several bins each of cool white (the ones without the designation of "warm" or "neutral" are all cool), warm, and neutral. The differences between the choices are the color bins and brightness bins. Color and brightness bins let you target specific properties in a particular model of LED. For our purposes, we want the brightest bins we can get (it's literally free light - these LEDs will all consume the same amount of power, but the brighter bins will turn more of it into light energy.) Color bin is not quite as important (or, at least, we don't yet know how important it is in a refugium application). If you want the details, you can look at Cree's datasheet and binning and labeling guide:

http://www.cree.com/products/xlamp_xpg.asp

Note that the warm white LED is (likely) the best spectrum for algae, but it's not available in as high-efficiency bins. If I were designing a refugium LED array, I'd probably start with a 50/50 mix of cool white and warm white XP-G, in the highest brightness bins I could get. From cutter's selection, that would be XPGWHT-L1-1B0-R5-0-01 for cool whites, and XPGWHT-L1-7B4-Q5-0-01. These equate to roughly 6600k and 3100k, respectively. The blending of the two would give you a pretty full warm spectrum.

Another approach might be to use all neutral whites, such as XPGWHT-01-5B1-R4-0-01. This is approximately 4250k. Depending on how you built your array and how dense it was, you might get color separation ("spotlighting") with the two-LED approach above, so this single neutral LED approach might work better for lower-output arrays, or arrays spread over a large area.

Which brings us to the next challenge. How many LEDs do we need and how to we spread their light out across our refugium. On a display tank, this isn't quite such a problem, because we want very high intensity so we just pack the LEDs in and there's no problem. But I'm guessing the typical refugium needs a much lower intensity, which means one of two things:

1) Keep the LED count high and run at lower current. This will result in a nice even spread of light, but will cost more upfront.
2) Use a typical current (say, 700mA) and reduce the LED count. This will be cheaper upfront, but might result in uneven coverage - the light intensity will drop off between LEDs.

Optics can help with this spacing problem, but most optics are intended to narrow the spread of light, not widen it. There are some diffuser optics out there, but they're much less efficient, and probably not worthwhile.

And those are my thoughts. I'm right in the thick of this at the moment because my 360g will be on line soon and I'm hoping to use LEDs to grow algae in the sump! If/when I have a build, I'll be sure to post details.

[der_wille_zur_macht]

Originally Posted by AcroSteve

Conversely, I would like to at least consider an off the shelf fixture

If you're talking about off the shelf LED fixtures, fuggedaboutit. They're almost universally built with junk LEDs (i.e. inefficient to the point of being no better than other types of lighting) and/or are wildly overpriced. The industry isn't far enough along yet to produce good off the shelf stuff at reasonable prices. You'd be better off sticking with a traditional refugium light, or DIY'ing if you want LEDs.

[zangmann]

There is actually a pretty long thread on another forum talking about this.
Google 'Modern LED scrubber light'

The thread compares both a pre built, off the shelf system as well as the DIY method.

[AcroSteve]

Originally Posted by der_wille_zur_macht

If you're talking about off the shelf LED fixtures, fuggedaboutit. They're almost universally built with junk LEDs (i.e. inefficient to the point of being no better than other types of lighting) and/or are wildly overpriced. The industry isn't far enough along yet to produce good off the shelf stuff at reasonable prices. You'd be better off sticking with a traditional refugium light, or DIY'ing if you want LEDs.

That is my impression also, but I don't get out much.



What I am picturing is a fixture much closer to the intended target than in a display. My cheato consistently grows at the water surface and the tank is only about 10" deep. That will definitely increase the "spotlighting" of individual led's and makes me think that an array of a single model would work best. However, as you mentioned, a well matched option may not exist, and a mixture of two types may work better.

My current setup has about 10" of clearance above the 12x30 surface of the refuge tank. I am concerned if I get the lights high enough to blend the two sources, I might get too much scatter and loose light outside of the tank.

If the pair of led's had the same PAR, the 6600k and the 3100k would average to 4850k. The single neutral whites is a little lower at 4200k. I suppose I could get some of all 3 types and try it both ways, but that seems a little excessive.



I have several heat sinks that are 4.5x6. I am thinking I could get enough led's in one of them to do the fuge. What do you think?



Boy Cutter's site really is a mess.
Forgive my ignorance, but what is the "XPG on Metal Core PCB:"?





Thanks for the headsup Zangmann. Looks like I have some reading to do later.

[der_wille_zur_macht]

Originally Posted by AcroSteve

However, as you mentioned, a well matched option may not exist, and a mixture of two types may work better.

In addition, a mixture gives you a little bit more control - you can dim the two types of LED separately and essentially vary the spectrum of the output, though of course you'll be varying the intensity at the same time.

My current setup has about 10" of clearance above the 12x30 surface of the refuge tank. I am concerned if I get the lights high enough to blend the two sources, I might get too much scatter and loose light outside of the tank.

Light "scatter" or waste is a total non-issue in a properly designed LED rig. That's what optics are for! If your illuminated area is 10% bigger than you want, put on optics that are 10% tighter. Of course you're working within the constraints of available optics.

I suppose I could get some of all 3 types and try it both ways, but that seems a little excessive.

Yeah, but somebody's gotta do it. Then we'll all know.

I have several heat sinks that are 4.5x6. I am thinking I could get enough led's in one of them to do the fuge. What do you think?

Depends on the number of LEDs you want, drive current, heatsink design, air movement near the heatsink (a fan changes things significantly), etc. Can you post a photo of the heatsink? Even if it's sufficient thermally, it's a small area, compared to the dimensions of your tank, and you might have trouble getting even coverage.

Boy Cutter's site really is a mess.
Forgive my ignorance, but what is the "XPG on Metal Core PCB:"?

HP LEDs are very small surface mount devices. They're HARD to handle for manual assembly (i.e. us hobbyists). Hence most vendors pre-solder them to metal core PCBs. This gives us a package that's MUCH easier to deal with, from an assembly perspective, AND makes thermal management much easier, since a metal core PCB conducts heat away from the LED very well. So, typically, us hobbyists buy LEDs on MCPCBs (sometimes called "stars") and screw or glue these directly to a heatsink, then wire things up.

Thanks for the headsup Zangmann. Looks like I have some reading to do later.

I just found the thread he's referencing. It's got a lot of good material in it, for sure.

[AcroSteve]

Originally Posted by der_wille_zur_macht

HP LEDs are very small surface mount devices. They're HARD to handle for manual assembly (i.e. us hobbyists). Hence most vendors pre-solder them to metal core PCBs. This gives us a package that's MUCH easier to deal with, from an assembly perspective, AND makes thermal management much easier, since a metal core PCB conducts heat away from the LED very well. So, typically, us hobbyists buy LEDs on MCPCBs (sometimes called "stars") and screw or glue these directly to a heatsink, then wire things up.

So the options are for different configurations?

I found the description of the 1st 3 at the bottom of this page.
http://www.cutter.com.au/products.ph...Metal+Core+PCB

But what are the more expensive options? I doubt that it matters, but I am curious.

I have two rather similar heat sinks to choose from. I have several of these each. I like the one on the left better.

[der_wille_zur_macht]

Yep, the options are for different sizes of MCPCB and/or multiple LEDs per MCPCB. 99% of people will be happiest with the standard star configuration, which is XPG-20-STR or something like that. The more expensive options are several LEDs per PCB, which you definitely don't want in a refugium application (you want low density, not high).

At a quick glance those heatsinks don't looks as beefy as the standard heatsinks people are using, which are probably overkill. I'd keep LED count per heatsink low, and use a fan. That's the safest route. Of course, you can experiment and see what sort of temps you get. I'd probably use the sink on the right in the photos, and mount 3 or 4 LEDs on each. I'd use two of these such units for a total of 6 - 8 LEDs. I think you said you had 10" of clearance above the 'fuge - I'd probably go ahead and mount them at 10" (or as close as you can get, allowing space behind them for a fan). The "sides" of those heatsinks will make a convenient way to mount a splash guard.

[AcroSteve]

Originally Posted by der_wille_zur_macht

At a quick glance those heatsinks don't looks as beefy as the standard heatsinks people are using, which are probably overkill. I'd keep LED count per heatsink low, and use a fan. That's the safest route. Of course, you can experiment and see what sort of temps you get. I'd probably use the sink on the right in the photos, and mount 3 or 4 LEDs on each. I'd use two of these such units for a total of 6 - 8 LEDs. I think you said you had 10" of clearance above the 'fuge - I'd probably go ahead and mount them at 10" (or as close as you can get, allowing space behind them for a fan). The "sides" of those heatsinks will make a convenient way to mount a splash guard.

Yea, I would like a little longer fin length, but if these work out, the price sure is right.

And I was thinking the same thing about the splash guards

[therman]

I just built a light last night with 4 CW XP-Gs to run over some chaeto. I used about a 4" heat sink, no fan, and no optics so it was a piece of cake to put together in about an hour with a 1000mA buckpuck, and an old laptop power supply (18V).

Its only been running about a day so I can't tell you how well the chaeto grows, but I imagine it will do fine. I made a ghetto apparatus out of a 1" PVC tee and some zipties to hold the ball of cheato on the long ends of the zipties in place under the light. The weight of the tee keeps it from drifting down towards my return pump at the other end of the sump.

[Obi-dad]

I think LEDs will be a good idea in some people's fuge setups like mine - my fuge is in my sump, and the light from the LOA unit spills over into the compartment with the skimmer - so I get coralline algae growing inside my skimmer. With LEDs, I can limit the light to the fuge compartment.

And as another benefit, it will reduce the heat into the water. I am going to try a mix of warm and cool white.

[AcroSteve]

I am pretty sure I am going to build my controller based on the 4101 chip. I hope I get around to ordering some parts this week.

[AcroSteve]

Well, since I will be soldering some rather sensitive items, I was thinking of getting a better soldering iron - something that is controllable.

So I was thinking of getting a little solder also. I have a few feet of .040 left so I thought I might get some solder with my iron. My lord, I had not noticed solder got so expensive.


What is the largest dia that I should expect good result out of with these components?

Any particular solder a better value than the others?

[AcroSteve]

Ahh, get some solder with some lead - like a 63/37 and the prices get more reasonable.

http://store.sra-solder.com/product.php/6108/17

[der_wille_zur_macht]

You WANT lead solder. Lead free solder works at higher temps and is generally a pain until you get the hang of it. The solder you linked to would be OK.

By chance, that vendor also carries the iron I'm currently using:

http://store.sra-solder.com/product.php/6145/22

It's basically a knockoff but it works fine. I use it for everything from tiny SMT to heat-hungry LED stars mounted on heatsinks.

[chernandez]

tagging