We don't work with depths that light gets effectively filtered out. The warmth of the color can easilly be changed by adjusting the balance of white and blue LEDs. Fine adjustment can be done with an adjustable driver.

I agree that the tri-Rebels provide great color blending (I use them on one tank), but using other colors really provides no great benefit to the corals. Heavier amounts of red can help with the growth of macros, but it can also cause problems with corals. The amount of red in a cool white LED typically is plenty to grow most macros pretty well.

I could be wrong about this, I've heard adding a few red LED's will add pop to the more reddish corals such as acans. Obviously, it would only be for aesthetic reasons but sacrificing 1 or 2 LED's for a red one every 2 feet might not be a bad idea if the tank has a lot of red corals.

If you need more red, you could substitute in neutral white LEDs. It raises the red output without sacrificing the blue much. Honestly, I have no issues with red colored corals, including a few acan polyps I have at the bottom of my 4g LED tank.

Added this to show what we're looking at as far as color temperature.The warm whites maybe too red after
all and I may go with some neutral whites instead as Evil suggested to me.I'll have to research it more , the
warm whites are more aesthetically pleasing to the eye though.

Keep in mind that that graph represents the ideal black body color temp plot. There are many ways to get to a certain color temp (which is painfully obvious in MH bulbs). Most LEDs that you find are not the ideal versions, and you have to pick the appropriate tint bin, which is very difficult sometimes.

What are you basing the comment thatwarm whites are more pleasing to the eye on? In the home, it's what we have been conditioned to deem pleasing to the eye, and unfortunately the CRI (Color Rendering Index)usually follows that trend. What we need to think of here is how to appropriately simulate the conditions that our corals would see, which is typically heavy in blue.

Personal taste really for the warm whites.I am drawn to more warm than cool colors , nothing scientific.
True we must try to recreate the corals natural light conditions.My approach is to make a DIY LED fixture
that is pleasing to me without overly sacrificing the corals needs.

My only concern going to warm whites is the potential for pest algae issues.

Ok, how about a bigger design then...

48" long, 24" wide, 24" deep tank.

40 degree reflectors obviously, I'm thinking 2 to 1 white to blue ratio, with a total of 96 xr-e's.

My biggest problem though is power supply design... that's an awful lot of expensive buckpacks

Help

Hey with a small voltage power supply does that mean you have to run at higher amp draw or can you just not run as many leds. I going with the last one...
meaning instead of 6 at 24vdc-you can only run 4 at 12vdc per buckpuck?

Might be a little light on LEDs. It would require spacing that could cause spotlighting. Moreso front to back. With 96 LEDs, you are looking at 4 rows of 24. For a 24" wide tank, I think going up to 6 rows would give you better results. Adding a few more tot he rows would get you closer to a 1.5" spacing that will work better for 40 degree optics.

Powering it is always going to be expensive. The Meanwell ELN drivers are your best choice right now for running lots of LEDs. The ELN-60-48 will allow you to run 26 LEDs (2x13) at 750mA, and 13 LEDs at 1A. Getting the dimmable version is a little pricey right now.




What you can do is run smaller strings at a lower voltage, but run multiple strings in parallel. The driver has to support a higher current to get the most out of the LED though. For example, if you want to run 6 LEDs at 1A, you either have a driver running 1A at 24v and run all six in series, or you have a driver running 2A at 12v and run 2 3 LED strings in parallel. Works out the same, but it's harder to find drivers with higher currents. The Meanwell drivers are probably the best for this.

Any thoughts on the number of LEDs for a 2.5gallon? Thinking about putting a reef on my desk at work...

lol!

Paul

Ideally, 10. Thats what I use in the single Satellite retro that fits perfectly over the 2.5g tanks. You can go less than that, but the coverage suffers a bit.

So like this:

X X X X
X X X
X X X X

?

2.5" spacing from corner to corner across and from edge to edge on the diagonals?

Best,

Paul

Well, thats more like 13, but who's counting

You can do that, but it's not necessary. A simple 5x2 worked out perfectly for me.

More like 11 but who's counting.

You could go
x x x
x x x x
x x x

But a 5x2 would work better with the size of a 2.5g tank.

Pfft. 11, 13, I'm sick and I say it's the same

I don't see much need for three rows on that narrow of a tank. Doesn't mean you can't do it though.

I assume that "lm" is lumens? More lumens = better for corals on white lamps?

Thanks,

Paul

When talking stricly about LEDs, yes. A higher lumen white will provide higher PAR numbers. You can't use lumens as a comparison to other light sources though.

On my 4 gallon I am going to do 2 x 6...

What type of 4g tank?

do you have guidelines for spacing with different degree optics and depths?
ie
40 degree at 12" at 24"
60 degree at 12" at 24"

Maybe we can put together a chart?

Any updates on writting more info on the superflux and other leds, didnt you mention a new section for them?

Spacing doesn't really change for the depth of the tank. You still have to light portions of the upper sections of the tank.

Typically, I have suggested ~15." spacing for the 40 degree optics, and 2-2.5" spacing for the 60 degree optics.

I haven't had a chance to work on the other LED section. I still need to finish the last portion of this guide.

For the Rebels with 3 LED's on them, are the considered 3 seperate light sources for calculations, or are they just one LED? Also, do they make a 60 degree optic for Rebels that you know of?

How do you attach the back of the LED PCBs to the heatsink? I assume that you drill/tap a hole and then screw them on through their mounting block?

Do you know of a cheap place to get a custom heatsink made for mounting LEDs to? How does the Optic stay attached?

Also, if using the 3 LED rebels, should I mix colors on each lamp? Do like 2 white and 1 blue and 2 blue and 1 white alternating to get a better blend of color for the tank?

I'm a pretty good hand at soldering, and I think this is something I can do.

Thanks,

Paul

Not sure what you mean here. Calculations for what?

They only make a 25 degree lens for the triple Rebels. While this setup has some nice advantages, it gets expensive really fast, and is really only good for super high light setups.



Drill and tap is the prefered way. Gives maximum contact area and pressure for thermal transfer. Thermal expoxy is an option, but can lead to higher die temperatures.



Chris at Nanotunners can do truely custom heatsinks, but you would have to model it yourself to keep costs down (not Sketchup, a real CAD program that can export to IGES, STEP, or STL). If you want just a big heatsink, HeatsinkUSA is a good source for big cheap heatsinks.



You can mix up the colors any way you want. It will offer the best color blending by far.



Soldering wires and through hole components is very different than surface mount. Can't use a soldering iron in the typical sense here. Hot air, or a reflow setup is needed here. There are some simple ways to get this done on the cheap at home. Either way, Rebels are not an easy LED to work with.

So the opening above my tank will accomodate an 18" wide by 40" long grid of LED's. If I did 6 rows of 20, you think that would work well with the 40 degree optics? Speaking of the optics, closest I found were the Carloc 20mm wide ripple lens to 40 degrees: http://www.ledsupply.com/10211.php

Am I missing an optic out there?

For power supply, this gentleman out of germany has diy kits with linear regulators for under $3 each, and each can power 6 LED's on 24VDC input. So thinking of getting 20 of those kits, and powering them off multiple 24VDC power supplies: http://www.mpja.com/prodinfo.asp?number=16854+PS

Good idea / bad? Thanks again for all your help

I used to do surface mount component replacement at my last place of employment. I'll need to get some tools, but I've done it before (The LEDs can't be as bad as the micro resistors we had to do to fix a CPU temperature probe).

25 degrees is far too acute to be worthwhile on a 2.5gallon tank, too shallow, right? I assume that I can run them without optics pretty easily, right?

As to the CAD design, I've got some friends that use CAD software regularly, I'll see what they can generate for me.

Thanks,

Paul

Ooo, I has those.

My heatsink plans



It shall be epic.

6 rows sound better, especially with an 18" width. Might wat to still use 24 LEDs on the length. That will get you closer to the 1.5" spacing for the 40 degree optics.

Those lenses will work. Cree also makes a 40 degree lens that fits nicely on the LED without adhesives. You can get them from Cutter in Australia.

Linear regulators work, but they generate a lot of heat. If they are LM317 (or similar) based, I wouldn't do it. If it's transistor based, then they are much better, and run a lot cooler. Still won't be as good as a true buck converter, but certainly cheaper.




Sounds like you have a leg up over most people then.

There is no need for optics on a 2.5g tank, unless you want some seriously high light levels. Running triple rebels you are already above 70W MH levels. With a lens that tight, you have to run so many LEDs to get coverage, it's not worth it for such a small tank. Plus you would have to run at really low currents to not burn everything (which could be a good thing).

I'll check out the 40 degree from cutter, see which is more efficient. Thanks

Here is a link (in german though) to the guy making the diy led constant current driver kits:

http://www.ledstyles.de/ftopic6528.html

It uses the Catalyst CAT4101 constant current low-dropout driver as the main component.

Another 24 then.. so 144 cree xr-e's with 40 degree lens... yowzer 1:1 white to blue, or 2:1 white to blue ratio (ala aqua illumination)?

Any reason why I shouldn't buy the whites from dealextreme (R2, WG bin), seems a lot cheaper than ledsupply or cutter:

http://www.dealextreme.com/details.dx/sku.15943

Thanks!

I've seen that driver before. Should work ok, although I'm not convinced they can get 90% efficiency from it.

Color ratio is down to you. 1:1 will get you about a heavy 14K look. 2:1 should be in the 12K range.

Only complaint I have about any of the LED purchased from DX or KD (other than the shipping delays) is the quality of the pcb and the installation. Not the best IMO.

hey evil what would you recommend for a jbj 24 gallon setup?

I think if I get 85% efficiency I'll be happy, for the price hard to go wrong since I'll need so many.

When buying 72 of them, I'm willing to tolerate cheap circuitboards for $2 less per

My 4 gallon is a Finnex. It is a sweet little rimless...Love it, would like another one but I have spent more money on this little 4gal than I did on my 75 gallon reef.





ok when is the next installment of the diy led manual coming....I am anxiously awiating it...

Thats the tank I have with the LEDs. 10 LEDs is plenty.

I hope to have time next week to work on the next section, but no guarantees that it will be finished then.

Evilc, I'm wondering, do the blue LEDs give as much par as an equivalent white LED? I would assume NOT based on other lighting sources. If not, any idea how much you would lose with the blue LED.

I am just wondering if it's feasible to run lights with a substantial majority of blue leds to white (i.e.4:1).

I'll take a stab at this. The blues aren't going to be anywhere near the par of the whites. As for how much of a difference, I'm not sure. I would guess that there would be quite a difference. As for your 4:1 ratio you may not want that much blue, I would think it would overpower the white. Maybe a 3 blue to 2 white would be a little better. Plus if you use dimmable led drivers you can dial in just the right amount of blue that suits you.

Actuall I believe I read somewhere that the blue leds had a very high par value, due to the fact that the spectrum range falls right where chloraphyll needs it. Blue just seems dull to us because it is not a color that our eyes are very sensitive to.

At a 4:1 ratio you tank would look very atinic.

r3tics got it. Royal blues produce as much or more PAR than cool whites. I can't say for sure as to if it's more or not because most PAR meters don't measure the blue end of the spectrum very well and report low.

When I did tests on my fixture, the royals posted only slightly lower numbers than the whites, mainly because I'm only running them at 700mA versus the 1000mA of the whites.

So, color aside, it's better to run more blue than white for growth?

Interesting, I assume that equal parts royal blue and reg. blue are normal? I could do my 10 gallon with 10 each of white/blue/royal blue in rebels and get 30 LEDs on a 2.5" tank..

Hrmmm,

Overkill?

lol.

Paul

Absolutely no need for 30 LEDs on that size tank, no matter the brand. 10 is more than enough. I prefer royals over regular blues, mainly for fluorescing, and a deeper color tone.

With the PAR about equal between royal and cool whites, the balance will be down to what your color temp preference is. 1:1 gets pretty close to a heavy 14K. 2:1 gets a pretty nice 12K, especially with the Rebels. This is what I'm running on one tank.

Here's one for you evil. What are you're thoughts on runnning the wiring between the heatsink fins. As in drilling holes near each led allowing wiring to pass through. I think it would give a much more clean and professional look to the fixture. I think it would handle the heat, what do you think.

Thats how I do it. Makes for a much cleaner installation.

On a BC14, for example, do you wire your fans to the same power supply that powers the two drivers for the LED's? What does that wiring diagram look like?

the bc fans are 12v. if you wire the fans in series, then you can use your power supply to power the fans and the LEDs. you would connect one positve and one negative from each fan and wire those two together. at this point you should have one positive left over on one fan and a negative on the other. those go to the respective leads from the ower supply. i hope i didnt confuse you

No, that makes perfect sense. However, in Waterproof's BC14 LED build, he added a third fan to draw heat directly off the heat sink. How would the wiring on this work? You can't wire it in series with the other two on a 24V power supply, I wouldn't think, since this would be a 36V branch of the circuit.

You could wire two of the fans in parallel. so you have

Allright evil, how's this array look? Total of 39 leds, it would be 20 royal blues and 19 whites. spacing is 2in between each left to right and 2.5in top to bottom. I think I would run it without optics and see if everything likes it and then switch to 60 degree optics if I need to.

That rendering is amazing. I can't wait to see this finished. Take pictures as you go, should be a cool project.

Best,

Paul

Drop one LED from the center row, and shoft everything over 1" so they are centered between the front and back row. Makes color blending a lot better.

What i would like to know is when taking those number:
12" - ~500PAR
24" - ~200PAR
and compare them with Mh or T-5 what can we expect?