The 'Evil Cluster' revisited

[blasterman]

- Long post warning folks -

 

Awhile back EvilC built a quad cluster, Bridgelux N1202 / Cree Royal LED light to test out a new heat-sinked he proto-typed, and as we all recall not only was color amazing with this rig but you could probably measure PAR from the International Space Station...on a cloudy night :-)

 

Since then I saw a few builds based on the concept of 3watt royals circling a large Bridgelux array, but nothing recently. This surprises me because it's a, well, 'Evil' combination that has excellent scalability, unsurpassed PAR and color, and is quite flexible. Hence I refer to it as the 'Evil cluster in this forum and others. My own tanks are too small to efficiently utilize this design being an apartment dweller, but given I get so many questions about larger tanks I wanted to build a single cluster, and try some of our up-dated tweaks on it. This also gives me a basic rig that I could show reefers in my area due it's small size and mobility.

 

The original design was I recall eight XP-E royals circling a Bridgelux N1202 array with the Bridgelux using a wide Ledil 'Brooke' reflector and the XP-Es running medium optics. The light cones then overlap each other vastly eliminating color shadows and producing for all intents and purposes a seamless light. I built a single cluster about a month ago following Evil's original design closely, but having to make some upgrades due to new LED's. The N1202 Bridgelux is obsolete, which I replaced with a BXRA 950-B, and obviously XT-Es replaced the XP-E's. The 950 B runs at 500mA and ~21volts, and throws 1140 lumens at 4000k, which is 108 lumens per watt and rather astonishing improvement given the older N1202. The Brooke reflector worked perfectly on the large Bridgelux, although it's a bit wider than the optics I used for the XT-E (RapidLED 80's which seem like 70 to me). In any respect, the light produced by the combination was startling and easily had the best package intensity and color I've yet seen in *any* reef rig.

 

Held several feet above my 15long colors matched my current XT-E / Bridgelux N402 rig, and were actually a bit better upon scrutiny given the newer phosphor set on the 950. I then made some other tweaks including adding a standard 470nm blue Cree, which added some punch to coloration but did not affect color temp much. However, two standard blues did produce a drift to the cyan/green side, so I left it with just one. I also turned off a single royal given I didn't have a spare dimmable driver, and this to my eyes yielded something close to 12k. This improved color even more, and was planning on experimenting with a deep red added to the mix after freeing up some adjustable drivers from other projects. But, then I got busy...

 

I got an E-mail back from a reef store in a nearby town, and decided to head out there to get some montis I've been hunting around for. Then I remembered these guys had mostly low profile, rimless tanks with halide pendants, a lot of diverse coral, and we're fun to chat with. I quickly decided to haul my test light out there and see if we could do some comparisons, and hastily soldered everything back with any spare wire I could find. Only problem was I had removed the optics weeks ago because they were in the way, so the light would have to go 'commando'.

 

Reef shop had about a dozen large rimless tanks, and pretty much healthy everything from zoas to LPS of all flavors to SPS, although they didn't have much Acropora. They did have a lot of montipora, caps and encrusting. They were mostly running Reeflux 14ks 250s on a variety of ballasts, and a single 10k. My own opinion is the Reeflux is a bit 'monochrome', but seems to be well liked by a lot of reefers. Phoenix might have a bit better color, but it depends on who you talk to. Guys manning the shop we're more than enthused to let me bring the light in and see how it compared since all we had to do was push the pendants out of the way. So, I brought it in an plugged it in - results follow. Sorry for no pics, but the conclusions were a total 100% concensus between myself and the staff, and above all I feel this was the most important part.

First observation was that there was no radical difference in color cast between the single Evil cluster and the Reeflux. The Evil cluster was warmer, but happily in between the Reeflux 14k and 10k. Neither light gave you a 'apple and oranges' knee jerk response nor the exagerated comparisons you see on youtube. This was a good thing because we could focus on the more subtle differences, and those were quite obvious.

 

The Evil cluster clearly torched the halides in terms of actinic response. This wasn't the artifical 'I'm a newb and cranking up my royals to impress my buddies' kind of actinic response, but seemed quite natural in relation to either light. The 14k halides had some actinic on their own like any 14k halide should, but the Evil cluster had more, and the actinic response had significantly more depth. Likely due to the cool blue being incorporated, which was a big reason I added it. Actinic reds and oranges were a huge win for the Evil cluster, again likely helped by the cool-blue doing it's thing. LPS and softies we're clearly the biggest winner with the Evil cluster.

 

What really surprised me though was how well the Evil cluster brought out colors in large monti caps, both orange and red. Subtle purples and reds were visible with the Evil cluster, but totally absent with the halides. From tank to tank the story was the same, and no matter what angle or height we held the lights the Evil cluster simply out-classed the halides in every tangent. I tried and tried to find some colors or contrasts the halides were better at and there simply weren't any. Unlike the complaints we see about LEDs 'missing something compared to halides' this was clearly the inverse.

 

There was however one nit against the LEDs that surprised me. There was just a bit of disco flicker in shadows when the light was elevated higher than normal. Not a lot, but just a bit to notice. Shimmer was the same between the two light sources, but I wouldn't have thought this with a bare light. When I tested the light at home with optics on there was zero disco, so maybe it's just the exception to the rule and needs optics to be '100% disco free'. I only noticed it because I'm sensitive to it. Most reefers wouldn't and you had to squint to notice, but to be fair it was there.

 

It would have been nice to test out against some other commercial LED rigs, especially those I criticize for being a lot of marketing and poor color, but they didn't have any. It was unanimous though which light was superior in terms of color, and the specific reasons why. I should note there were additional tweaks that could be made such as adding a far red, or running the light brighter than it's 700ma / 350ma source, but it wasn't necessary. Anybody questioning the superiority of quality neutrals or LED's in general would have been convinced quite easily. A T5 / halide hybrid rig would likely keep up better, but by themselves the halides just weren't up to it.

 

[Veng]

Wow, very long post. I'll be sure to read tomorrow when I've had less to drink

[phasezero]

There was just a bit of disco flicker in shadows when the light was elevated higher than normal. Not a lot, but just a bit to notice.

 

I should note there were additional tweaks that could be made such as adding a far red, or running the light brighter than it's 700ma / 350ma source, but it wasn't necessary.

 

Do you think the disco is more apparent without optics since the spread of light isn't as even across the lit area compared to an optic where the lit area is focused ?

 

Do you know if the LED spectrum changes in relation to it's driving current? I ask this because in my setup with using 12RB + 2B @ 1A, from about >90% it seems like the overall tank becomes a much cooler blue, rather than just becoming brighter. I don't know if any of that make

[jedimasterben]

Very good read blasterman.

 

Where did you get the Bridgelux LED? How big of an area did it cover? Any chance we'll get PAR readings?

<-shades required to look at it lol

 

 

I would be very interested to try something like this over top of my new shallow (48x24x12). This combined with exotics, 660nm, 495nm, and 420nm.

 

And whoa, if you ran that 950B at 1000ma, the datasheet says it should put out over 1900lm!

[jedimasterben]

The more I think about this the more I think its a cool idea, and this is what I came up with for a cannon:

 

 

Two of those bigass 950's at 700ma, 14x 440nm royal blue Rebel ES, 1x 470nm blue, 6x 420nm true violet, 4x 660nm red, 4x 495nm turquoise. Each on its own dimmable driver, grouping the LEDs as closely together as possible (space was left in the diagram because otherwise Illustrator wouldn't snap them in place lol). Would need to cover a 24"x24" area, so two of these clusters on my shallow tank. I think with the true violets added in that it should be good enough for SPS almost anywhere in the tank. Comes to about 110w, and would be cooled by an 8.5"x5.5" heatsink with active cooling.

 

Total cost between LEDs, drivers, optics, heatsinks, misc, would cost me ~$225 apiece.

[blasterman]

Do you think the disco is more apparent without optics since the spread of light isn't as even across the lit area compared to an optic where the lit area is focused ?

 

That's a good theory, and one thing I noticed when using Bridgelux or any large array is their coverage is different (wider) than bare Cree's. They don't match perfectly, unless you use optics, then you have different issues. Again, disco wasn't really that bad and I've seen a lot worse, but it was there. I was really, really splitting hairs though and we were looking at any little differences in color. Using an XM-L at 2.5 amps or so and changing the royal ratio a bit would likely eliminate the issue on teh bare version. I did not see disco in the optical rig, but then again I hold to hold the thing 4' above my tank to keep from being blinded.

 

Do you know if the LED spectrum changes in relation to it's driving current?

 

No...not unless the LED is over heating. However, white LEDs might not ramp up the same as royals because of efficiency differences near 1amp. That might be what you are seeing.

 

And whoa, if you ran that 950B at 1000ma, the datasheet says it should put out over 1900lm!

 

Running the 950b at 350mA, and there's a lot of head room left obviously. It would take three or four clusters to totally match the out-put of the 250 halide, but that's half the wattage using no optics. Game over either way.

 

Where did you get the Bridgelux LED? How big of an area did it cover? Any chance we'll get PAR readings?

 

Newark and Digikey have them, but watch out for their Vf and current ratings because they aren't 3watt LEDs. Evil posted PAR readings on his four head, and mine would be similiar - just more efficient because of newer LEDs.

 

IMHO, I'd use four neutral XM-L's for your tank in a square config for more even coverage.

[DaveFason]

Cool stuff blaster. I've done a few tests before the 13Up board with the same set up using RB ES/Rebel Blue and found it nice BUT the "disco" effect was there. Even when I added optics, with a highly agitated surface it made it worst than no optics.

 

The hard part is finding dealers that make FR4/MCPCB boards that work directly with those LED's and others. I found you could find the cheaper Bridelux but nothing besides that.

 

Glad to see you still testing away!

 

-Dave

[jedimasterben]

Running the 950b at 350mA, and there's a lot of head room left obviously. It would take three or four clusters to totally match the out-put of the 250 halide, but that's half the wattage using no optics. Game over either way.

I tried imagining them ran at 1A and it made my brain hurt lol.

 

Newark and Digikey have them, but watch out for their Vf and current ratings because they aren't 3watt LEDs. Evil posted PAR readings on his four head, and mine would be similiar - just more efficient because of newer LEDs.

Yeah, they are 10-30w depending on the amperage.

 

Ok, so they should be similar to Evil's. Cool beans.

 

IMHO, I'd use four neutral XM-L's for your tank in a square config for more even coverage.

Ran at what amperage? 2A-3A? I wonder how many royals to run with them. I'll have to do a search for it.

 

Cool stuff blaster. I've done a few tests before the 13Up board with the same set up using RB ES/Rebel Blue and found it nice BUT the "disco" effect was there. Even when I added optics, with a highly agitated surface it made it worst than no optics.

 

The hard part is finding dealers that make FR4/MCPCB boards that work directly with those LED's and others. I found you could find the cheaper Bridelux but nothing besides that.

 

Glad to see you still testing away!

 

-Dave

Those 13- and 7-up boards are pretty cool, but wicked expensive!

[Veng]

The more I think about this the more I think its a cool idea, and this is what I came up with for a cannon:

 

 

Two of those bigass 950's at 700ma, 14x 440nm royal blue Rebel ES, 1x 470nm blue, 6x 420nm true violet, 4x 660nm red, 4x 495nm turquoise. Each on its own dimmable driver, grouping the LEDs as closely together as possible (space was left in the diagram because otherwise Illustrator wouldn't snap them in place lol). Would need to cover a 24"x24" area, so two of these clusters on my shallow tank. I think with the true violets added in that it should be good enough for SPS almost anywhere in the tank. Comes to about 110w, and would be cooled by an 8.5"x5.5" heatsink with active cooling.

 

Total cost between LEDs, drivers, optics, heatsinks, misc, would cost me ~$225 apiece.

I'm a little confused, you are using 6 dimmable drivers and the whole unit would cost you 225? Can you give us a break down on cost and what drivers you are using?

[jedimasterben]

I'm a little confused, you are using 6 dimmable drivers and the whole unit would cost you 225? Can you give us a break down on cost and what drivers you are using?

Bridgelux LEDs would be from wherever you buy them from at $11.40 apiece, optics/reflectors are around $5 each.

Royal blues would be Rebel ES from Steve's LEDs at $3.49 each.

Red & Turquoise from LEDGroupBuy at $1.99 each.

Violet I already have, so that cost isn't figured into my numbers. They are $4.50 each at LEDGroupBuy. The high voltage true violet will be out soon and will be about 3x time sthe price, but 3x the output.

Cool Blue are $1.99 each at LEDGroupbuy as well.

 

Drivers are from Steve's LEDs. They are special in that they have multiple channels per driver without having to run any in parallel. You'd need a quad for the four Bridgelux, a quad for the royals, a double for the red and turquoise, and a double for the violets. Quads are $39 each, doubles are $23 each, so $124 for those.

 

Power supply for the drivers is $~40 shipped from Amazon.

 

Heatsinks are from HeatsinkUSA, ~$32 each shipped.

 

Then you'd need optics (if you're gonna run them), wire, solder, etc, so your cost could vary depending on what you already have.

[jedimasterben]

IMHO, I'd use four neutral XM-L's for your tank in a square config for more even coverage.

Ok, if I do XM-Ls run at 3A, I calculate to 845lm. Your Bridgelux 950B runs 350ma for ~810lm, and you run six XT-E at 700ma for 1140mW each, for a total of 6840mW. If I use Rebel ES @ 1A, they put out 1390mW each, so I'd use five of them to get 6950mW.

 

Sound about right?

 

EDIT: Nahh, that's a few too many LEDs to use and buy. XM-L at 2A is 640lm, so keeping in the same 1:8.4 lumens:mW ratio of white to blue, I should shoot for 5375mW. Closest is 4x Rebels at 5560mW, so a 1:4 ratio of XM-L to Rebel ES. With that I'm calculation my upgrade to cost me around $450 still.

 

EDIT2: Or maybe I'll do six clusters instead of 8. Would be more cost efficient and still damn powerful combined with the true violets.

[blasterman]

You can drive XM-L's up to 3amps, and I've seen them run much higher for extended periods. However, 2.5amp drivers are quite common and that's what I'm in the habit of referring. Your math is otherwise pretty good...glad somebody is making the effort :-)

 

Yes, the big Bridgelux has way more headroom than the XM-L, but you simply can't pack any XT-Es around the big Bridgelux so it's wasted. The XM-L is also easier to match with optics.

 

For pure 'shock and awe' though the big Bridgelux emitters are unmatched. I just don't think I'd use them in a bare configuration, although it's possible that bumping three triple XT-E stars next to the Bridgelux die would help the issue. Be one helluva light, that's for sure.

 

I respect Rebels and the work luxeon has done with them along with Dave Fason's builds, but I have to concede I prefer XT-Es because of color. Rebels tend to run around 448nm....XT-Es around 450-452nm. The Rebels are a bit too purple for my tastes and seem to work better in cool-white based builds. Some, perhaps most reefers woulnd't notice the difference.

 

What irks me though is this is the second time I've gone into a reef store, and 'mopped the floor' with every light they had in-house, and yet most of the industry is still pimping cool-white based lights surrounded by a haze of PAR masterbating and other marketing.

[jm82792]

The concept of using a smaller array of high powered LEDs is nice because you can have a much smaller fixture.

(As stupid as it sounds) you are saving money on heatsinking material and the time of doing the build, especially here where shipping is a killer....

[jedimasterben]

You can drive XM-L's up to 3amps, and I've seen them run much higher for extended periods. However, 2.5amp drivers are quite common and that's what I'm in the habit of referring. Your math is otherwise pretty good...glad somebody is making the effort :-)

That's quite the compliment coming from you, thanks! You wouldn't believe how many calculations I do on a nightly basis trying different combinations of LEDs and drivers, different brand of LEDs, my documents folder is full of datasheets and Word docs full of math! Each configuration ends up being about the same price, though. Shucks!

 

I can get the drivers I was planning on using for my Rebel ES at 1A that supply 2A, so I would just run them there so as to not need a bazillion more royals to balance it out.

 

Yes, the big Bridgelux has way more headroom than the XM-L, but you simply can't pack any XT-Es around the big Bridgelux so it's wasted. The XM-L is also easier to match with optics.

And the optics don't cost $5+ each!

 

For pure 'shock and awe' though the big Bridgelux emitters are unmatched. I just don't think I'd use them in a bare configuration, although it's possible that bumping three triple XT-E stars next to the Bridgelux die would help the issue. Be one helluva light, that's for sure.

That would definitely be quite the spotlight, especially if the BL was run at 500-700ma. Could probably send signals to the ISS!

 

Plus, the look on peoples' faces when you tell them that there's only a single white LED under that ridiculous beam of light would be awesome!

 

I respect Rebels and the work luxeon has done with them along with Dave Fason's builds, but I have to concede I prefer XT-Es because of color. Rebels tend to run around 448nm....XT-Es around 450-452nm. The Rebels are a bit too purple for my tastes and seem to work better in cool-white based builds. Some, perhaps most reefers woulnd't notice the difference.

I actually prefer the bit more purple that they put out - though I have never seen them in person, I am relying on pictures and videos alone in comparison to those of CREE.

 

What irks me though is this is the second time I've gone into a reef store, and 'mopped the floor' with every light they had in-house, and yet most of the industry is still pimping cool-white based lights surrounded by a haze of PAR masterbating and other marketing.

This. I argued with one guy at a fish store that MH aren't the "best" and haven't been for a while. They are far too inefficient to be worth it anymore.

 

 

I'm gonna run some more numbers tonight, whether a 6x BL or 6x XM-L build would be best for the tank (it's rimless, so each cluster would have to cover a 16"x12" area). I may go Bridgelux just to say I did!

[Baroose_Le]

Holy crap, my head is spinning trying to understand LED threads like these. Are you guys all electrical engineers or something? I'm no dummy but I don't see any hope of doing my own DIY LED for the 150 gallon tank I'm getting if it is this complicated....

[ajmckay]

Nice post blasterman - thanks for making my decision of how to upgrade my lights (from 250w 14K hamilton MH) that much more difficult!!!

 

I've always really liked the idea of doing this type of cluster build (well, since the "original" evil cluster seen here http://www.nano-reef.com/forums/index.php?...20&start=20 .

 

I'm torn on lighting though because sometimes I like the more dramatic single/multiple source lights and other times I like the looks of a more even coverage like T5... I suppose I should just ask Evil if he's still got that cluster put together and ask if I can see it over his tank...

 

Right now I'm looking seriously at the 3up from LEDgroupbuy. I like the idea of being able to space 12 of those over my 40b for a quality look with minimal effort. On the other hand I've also looked at using manual clusters (1 XM-L NW to 2 XT-E RB) except that would cost even more, unless I could get away with fewer clusters. I suppose I could start with fewer clusters and add on as I need more, however, that would take some extra work to maximize the utilization of the drivers to not end up with too much wasted capacity.

 

Looking forward to some more photos

[DaveFason]

Thanks for the compliment blaster. I do try and get the higher nm RB's through my source. Like you said some can be purple but the later generation have been much more "blue" than "purple" ( pairing older ones with a few extra blues really off sets it ). I JUST got my NEX 5N rig up and going and will be shooting a few videos. My smaller test tank I have all types of corals/colors in it to show it off.

 

If you ever wanted to try a 13up for a month I would not mind sending one out. Do you have any new photo's videos of your new get up?

 

On the comment of running a smaller heatsink because of the smaller amount of LED's be careful. The larger high watt LEDs do put out a good amount of heat. You wont need anything crazy but you wont want to slim down.

 

For people reading this thread, PAY the extra amount and buy better quality LED's. It really does go a LONG way.

 

-Dave

[jedimasterben]

Holy crap, my head is spinning trying to understand LED threads like these. Are you guys all electrical engineers or something? I'm no dummy but I don't see any hope of doing my own DIY LED for the 150 gallon tank I'm getting if it is this complicated....

I'm not, not sure about the other guys, I just read a lot and know how to put basic math to use for this.

 

Nice post blasterman - thanks for making my decision of how to upgrade my lights (from 250w 14K hamilton MH) that much more difficult!!!

 

I've always really liked the idea of doing this type of cluster build (well, since the "original" evil cluster seen here http://www.nano-reef.com/forums/index.php?...20&start=20 .

 

I'm torn on lighting though because sometimes I like the more dramatic single/multiple source lights and other times I like the looks of a more even coverage like T5... I suppose I should just ask Evil if he's still got that cluster put together and ask if I can see it over his tank...

 

Right now I'm looking seriously at the 3up from LEDgroupbuy. I like the idea of being able to space 12 of those over my 40b for a quality look with minimal effort. On the other hand I've also looked at using manual clusters (1 XM-L NW to 2 XT-E RB) except that would cost even more, unless I could get away with fewer clusters. I suppose I could start with fewer clusters and add on as I need more, however, that would take some extra work to maximize the utilization of the drivers to not end up with too much wasted capacity.

 

Looking forward to some more photos

I'm the same way as you - I love the spotlight sometimes, sometimes full coverage. I'm torn lol.

 

A word of advice, though, if you are going to use XM-Ls for your whites, don't run them low-powered - you're paying extra for an LED that has the ability to run at extremely high amperages and get awesome amounts of light from them, so why get what you paid for out of them? Run them 2-3A surrounded by four to six royals depending on how you like your color.

 

Thanks for the compliment blaster. I do try and get the higher nm RB's through my source. Like you said some can be purple but the later generation have been much more "blue" than "purple" ( pairing older ones with a few extra blues really off sets it ). I JUST got my NEX 5N rig up and going and will be shooting a few videos. My smaller test tank I have all types of corals/colors in it to show it off.

 

If you ever wanted to try a 13up for a month I would not mind sending one out. Do you have any new photo's videos of your new get up?

 

On the comment of running a smaller heatsink because of the smaller amount of LED's be careful. The larger high watt LEDs do put out a good amount of heat. You wont need anything crazy but you wont want to slim down.

 

For people reading this thread, PAY the extra amount and buy better quality LED's. It really does go a LONG way.

 

-Dave

Do you have any comparison shots between the low and high nm RBs?

 

For people reading this thread, PAY the extra amount and buy better quality LED's. It really does go a LONG way.

Just wanted to emphasize this part. Don't end up like me, ordering ~$300 worth of LEDs, drivers, and heatsinks from Aquastyle and then realizing that I could have done a whole lot better. Gonna cost me another $350-450 to get it where i want it to be, though I am still selling my old LEDs and drivers for around $200, so that kinda makes it hurt less.

 

 

 

 

So is the Bridgelux running at 350ma or 500ma? I got confused along the way.

[jedimasterben]

Just compared your fixture to Evil's, just by the numbers though.

 

• Your fixture:
  Bridgelux BXRA 950-B
  1140m @ 500ma, 10.5w
  CREE XT-E x6
  5250mW @ 700ma, 12w total
  

• Evil's fixture (only one cluster, to make it fair )
  Bridgelux BXRA N1203
  1530lm @ 1050ma, 19.2w
   
  CREE XR-E x8
  6688mW @ 1050ma, 29.6w total
  

 

 

So yours puts out 75-80% of the light at 46% of the power, and that's a win in my book!

 

 

[jedimasterben]

Ok, played around some more and this is what I got:

 

 

 

 

1x CREE XM-L @ 3A

4x Rebel ES Royal Blue @ 1A

2x true violet @ 700ma

1x deep red @ 700ma

1x turquoise @ 700ma

 

Six pods of these over a 48x24x12 tank. If I had to buy everything - all LEDs, optics, drivers, wire, etc, it would cost less than $450 shipped including heatsinks (4"x4" from heatsinkusa). Since I already have the violet, red, and turquoise LEDs, though, it's only about $345

 

If I go with the Bridgelux, it'll cost me another $100 minimum, so CREE it is. Bridgelux would have been cool, though.

 

This should provide some awesome PAR and great coverage hung 20" above the tank (so 30" above the sandbed) with 60° optics.

 

I wanted to use some of Milad's new Ocean Coral White 3ups, but since I already have the red and turquoise, why buy them again?

[GothBoy]

Good to see you put this thread up. I know you PM'd me about an Evil Cluster a while back and now to 'see' how it works I'm even more convinced. Especially so given that the Bridgelux are available in the UK at a reasonable price when compared to the ultra-rare Crees

[blasterman]

Holy crap, my head is spinning trying to understand LED threads like these. Are you guys all electrical engineers or something? I'm no dummy but I don't see any hope of doing my own DIY LED for the 150 gallon tank I'm getting if it is this complicated....

 

Not at all. Clustering works ideally for bigger tanks like yours because you can build a single cluster, work the kinks out and your color down, and then just scale. Conceptually it's *easier* doing it this way on a bigger tank and you have far less risk of ending up with something that's under whelming. While I used the big Bridgelux, you can just as easily go with XM-L's. I will inist to my last breath that you must use neutrals, and like Dave said high quality ones. No Chinese crap.

 

One LED I've been interested in messing with is one of Citizen's linear LEDs that have super high CRI, but I can't find them. Running bare it's distribution pattern might be very nice for long tanks minus optics.

 

Sanjay Joshi is going to be a local reef-meet and giving a discussion on lighting, and his latest blog addressed lighting problems with LED (which I solved). LED's get a lot of negative hype in my area, so I plan on showing up with a test light and a whole lotta attitude.

[jedimasterben]

So it seems as though I'm mistaken about Steve's LEDs' royal blues - the specs are now 1620mW of flux and 440-450nm, so still more into purple, but that's where I like it. 1620mW is a buttload of flux.

 

So for a proper 1:5 lumen to flux (mW) ratio using XM-L at 3A or Bridgelux 950-B at 350ma, you'd need 2.5 instead of 3 or 4.

[blasterman]

1620mW is a buttload of flux.

 

At what, six watts? Can't find these specs anywhere on Steve's site.

[Psychosis]

Did you guys get the chance to see Evils array in person? It was amazing. Talked with him for about 20 minutes at reefstock last year, then watched in awe as he pointed this tiny light at the top of the Denver Aquarium and burnt a hole both through it and the sun above it. If I ever have a 4ft deep tank, I'd like one of those.

 

Sadly, I don't know enough about LED's specifically to really appreciate it, but I'm about to read up in preparation for a DIY build. Then maybe I can contribute more to this conversation haha.