So I just ordered my tank that I want to turn into a led lit tank. Its 20"x20"x15" tall. I want to be able to keep sps and clams. How many Leds do you think I will need? Has anyone built one with the ebay leds like these? Using half pure white and half blue. Do I need to throw in a few uv leds as well? Does it look like they will work? Do I need optics since its only 15" tall? Would a Meanwell LPC-35-700 48V work to power a line of 12 leds. Sorry for all the questions, but Im trying to get it all lined up before the tank arrives.

Even if you trust the quoted lumen rating those LEDs (and you shouldn't), they only put out half the light of the cree xr-e's that most people are using. Also optics are specifically made for individual LED types and I doubt you will be able to find optics for those LEDs and you would need them if you want reasonable PAR down to the sandbed.

You should check out evilc's DIY LED thread.

I was teasing Evil the other day about Satistronics gear

I atually ordered a pile of stuff from them, but only to screw around with, use for plant lights - gear 'smoke tests', etc. Aint going near my tank. They do have good prices on wide angle optics, and that's what I might use seriously. I know that specific optics are engineered for specific LEDs because of emitter size, but the truth is that this is less critical the wider angle you get. I'll pay for quality narrow optics, but wide angle 20mm Acrylics should retail for a penny a dozen.

I'd expect their 3-watt white LEDs to perform like 1watt Crees, and I'd be shocked if they hit 100lumens at 3watt. They'll also have a wide variance in bin tints and have the color uniformity of a 4yr old's birthday cake. Not to mention they won't like being driven hard. Not worth the trouble for serious tasks. Judging by their solder quality in the pics it makes me wonder if they are out-sourcing to N Korea.

The only advantage with the chinese knock-offs is their colored LEDs often work pretty good because the phosphor technology is pretty straightforward.

Get some decent LEDs like Cree XR-Es. They will be higher output and higher quality. You get what you pay for.

For quantity, use 32 LEDs in a 8x4 arrangement. No need for lenses. I would look at the Meanwell ELN-60-48D for a driver as it has dimming capabilities (compatible with may reef controllers), unlike the LPC series.

I just asked about the cheap ebay ones because they are half the cost. Just trying to save a buck or two. So then what would I need to be able to do what I want?

See above.

Thanks, apparently I posted before yours showed up

how many leds can the Meanwell ELN-60-48D run? (48v/4v=12) So I need one driver for every 12 leds? And should I add any uv leds?

The Meanwell can run 13 in series.

Yup, 13. At 1000mA, the max Vf of the LEDs is 3.7v, so you can just sneak in with 13 LEDs. I wouldn't worry about using UV LEDs for the time being.

Do you say that about UV LEDs because they just aren't there, yet? Or that the jury is still out for SPS and Clams? I'm starting my build soon (yeah!), but I think I'm going to wire for UVs but wait-and-see. I think...

so is there a huge difference in light output if you run the whites at 700ma instead of 1a? Also where is currently the cheapest place to get them right now?

It's two-fold. First, we really don't know what the minimum power levels need to be, or what the correct spectrum(s) need to be. Second. once those things have been figured out, it's a matter of sourcing the right LEDs for a reasonable price. Right now, short frequency UV (less than 380nm) gets really expensive really quickly. The 390-410nm UV LEDs that we have now are more expensive than the whites and royals, and have pretty low output overall.

So what size heatsink should I be looking at?

At a minimum, get a 16"x8.5" heatsink from HeatsinkUSA.

Would these drivers work if I can get a deal on them?

Sure, but you need to provide a 0-5v source for the dimming control. It's got to be a really good deal though. You can find Meanwells for less than that and they can interface directly with reef controllers.

Looks like the best I can do is $172 shipped for 5 of them

So where is the cheapest place to order from? The only part I know where to order is the heatsink. Ordering from heatsink usa. I want to go with the Meanwell ELN-60-48D's. And where should I order the Leds and what ones? Cree XR-e (p4, q4, q5, r2)?

Here's the scoop. I'm in roughly the same place as you are: looking to try it for the first time.

I can honestly tell you this though: These things are designed to last for ten years. don't skimp on your parts for something that will last you that long.

Do it right the first time and you'll be alot happier Leave being cheap to me.

Im not skimping on the parts, Im just trying to skimp on the price a little. Ive seen Cree xr's anywhere from under $5-$18. Just want to know the best place to order from.

I'd just get all the LEDs and drivers from nanotuners since they have both at a good price and you'll get free shipping. You can find the LEDs a tiny bit cheaper elsewhere such as ETGtech but you'll end up paying quite a bit more overall after shipping for everything.

2nded, but only if you live in the states.

i'm in canada and went looking for a more local option... it's not quite as good as Crees, but at least its in the same ballpark.

Yeah international shipping from the US sucks if you are a small business. Blame USPS

Ordered all my stuff today. I am getting 2 8.5"x17" heatsinks, 3 meanwell drivers, 26 cree q5s and 13 cree RBs. Figured I might as well run the drivers with the max amount of leds. So what would be the best layout?

Good prices

evilc66 tested and approved.

I know. Those are definitely the best prices I could find on the drivers for sure without doing a group buy. Have 3. Any ideas on the layout for the 39 leds?

Tank dims?

20x20x15. You said before to go with at least 4 rows of eight but I want to add a few more leds since I just got 39. 26 white and 13 blue

X.X.X.X.X.X.X.X
.X.X.X.X.X.X.X
X.X.X.X.X.X.X.X
.X.X.X.X.X.X.X
X.X.X.X.X.X.X.X

That's 38 LEDs and a lot better front to back coverage. Getting the pattern right for a 2:1 white to blue mix will be a little tougher to blend well.

Just remembered there is a corner over flow so I think I can do 4 rows of 8 and 1 row of 7.

would this work ok? The xxx's are the overflow.

W.B.W.W.B.W.W.B.
.W.W.B.W.W.B.W.W
B.W.W.W.B.W.W.B.
.W.W.B.W.W.B.W.W
B.W.W.B.W.W.Bxxx

That can work too.

So 2 questions. Ive been reading its not good to run the RB leds at 1000ma. Right now I have 13 on the way and am going to be driving them with the Meanwell 60-48d. Does this mean I should get 13 more RB leds and run them in parallel? Also whats the easiest way to dim them?

With proper heatsinking, the RBs at 1000mA are fine.

Easiest way to dim the "D" is with a 10v DC power supply and a 5k pot. Many times the power supply isn't 10v output though with a small load. What will be most accurate will be to get a 12v power supply (more common than 10v), use an LM317 to set your max voltage to 10v, and use a pot to adjust the output voltage from 0-10v. You could always get a Reefkeeper Lite and an ALC module and have it all automated.

So I need to find 2 12v wall warts (do the amps matter?) and 2 of These and 2 5k pots. Or do I need 3 of everything since Im running 3 drivers. 2 white and one blue?

Amps doesn't matter. You will need one power supply, one voltage regulator, and however many pots you need to control however many groups of drivers (2 in your case based on what you just said).

Ordered a LM317 to go with a 12v power supply and (2) 5k pots. Heatsinks showed up today. Do I need to drill and tap or can I just use thermal paste?

So will the 5k pots be ok?

Thermal paste is not an adhesive. You will need some way to fasten the LEDs down, whether it's by screw, thermal epoxy, or thermal adhesive pad.

The pots will be fine. You know you need additional resistors to set the output voltage of the LM317 right?

yeah. I ordered sometihng similar to this

SO then what works better. Drill adn tap with thermal paste or just use thermal epoxy?

Drill and tap wins hands down from a thermal standpoint. Epoxy works, and it's a lot less labor, but it's very permanent.

thermal glue seems to work, i've had mine glued for a few months now.. and still going strong.. i have removed 3-4 of them and all you need to do is keep wiggling a flat razorblade under them till they pop off.. i dont think it would be possible without a blade, it is strong..

Could also try twisting the star, most epoxies have fairly poor shear strength.

Which way do you turn down the internal pot? It doesnt stop when turned.

Counter clockwise. It should stop. It's only a 270 degree rotation pot.

So i have 2 of the 3 turned down. One doesn't stop when you turn it. Ideas? Also only 4-5 leds on each string is lighting up out of 13. Once plugged in they come on very dim. And when I hook up a 9v to the dimmer only the ones that are dim to start with work. Ive tested all the leds with 2 AA batteries and they all work. Now what?

Well I got all the strings working. Turns out I grounded a few of the leds. But still cant turn down the current on one of the drivers.

If the driver isn't adjusting the current, it sounds like that faulty pot is to blame. Contact the place where you bought it for a replacement.

I should be getting a replacement driver soon. Also waiting for a new blue led as one of the ones I got was a dud. But have everything ready to go once they get here. Have the heatsink drilled and tapped. All the leds are installed and soldered.

Got it all wired and hung. Still waiting for a ballast, but have the blues up and running. Not sure if I going to build a canopy around it yet. I kinda like the industrial look. Ill take a real pic once i get the whites up and running.