LED Build

[Zack]

I'm looking into updating my current lighting to LED. I have been talking with the service rep at rapid LED but would like some advice for people that have done this before.

Firstly, I need help deciding what heat sink to use. I am only using 12 LEDs, however I do not know which would work better for my 20" long system. They offer one heatsink that looks like an aluminum rod, and another that is more squarish. What are the pros and cons of each one.

Also, when wiring my LEDs, which option is better?

W B W B W B W B W B W B

or like this

W B W B
B W B W

Another thing I would like to know, is, is it possible to run say only the blue LEDs and have successful coral growth?

I have heard the trade off between using a 20K metal halide bulb and a 14K is that the corals will grow slower but will be more colorful.

Also, the service rep said that for my tank size (10 gallons) lenses are not necessary, however if I wanted to put a lens on, which size lens should I use?

Thanks!

Zack

[txg8gxp]

Any aluminum rod/u channel/ heatsink will work as long as it has enough thermal mass the dissipate the heat created. To also get front to back coverage I would run two rows over one on the led string. It is possible to run only blue leds, the par level will still be good but you will only have a 455-465nm lighting. Plus it would look like a 25+k...way too blue. Lenses will increase PAR and help prevent light from spreading out/over the tank. Lens angle will depend on how many leds, the led spread and how high the fixture is going to be mounted above the water. Give me some more info and I can give more direct info. As in, what mah are you going to power the leds at, what series emitters, and what size heatsink do you plan to run.

[Zack]

I will be using 9 LEDs, I do not yet know the spread, due to the fact that I have not decided on a heatsink yet. To be honest I have no idea of the height needed, but Mike from rapidled said 3" above my tank will suffice. The driver I will be using is either the Meanwell ELN-60-48D or the ELN-60-48P. As for the MAH i will be running them at, thats a bit in the air, I basically want the LEDs to put out the same amount of "benefit" as a 150 W MH.

If I want to run the lights at 14K, what ratio would I need?

[txg8gxp]

The ratio of led's will depend on the series of emitters. XR series a 1:1 works good, XP a 2:1 blue/white is good. Running the eln-60-48(d) they are capable of 1300mah. alittle too much for XR series or XP blues/royal blues. You will need to turn down the pot in the driver to limit output current. You will probably want the eln-60-48D not the P the D dims using varable 1-10vdc. The P uses PWM for dimming. 3" above the water would work fine if you spread the leds apart over the length of the tank. At only 3" I wouldn't worry about lenses, you wont really need the extra PAR or less you are going for a SPS system.

[txg8gxp]

Just remember, led's and saltwater don't get along. So hanging the fixture higher maybe a smart call

[Zack]

Would you recommend running the fixed current drivers instead?

[StevenSeas]

Just remember, led's and saltwater don't get along. So hanging the fixture higher maybe a smart call

or waterproof them ;)

I would go with the wider heat sink and put them in 2 rows like your second option states. Also it seems like you are wanting to run these off of the same driver. I would recommend to shell our the extra $ and get another meanwell. You can run them on the same 1-10V ps if you would like so its one less plug. that way you can tune the blues and whites individual to get just the hue you are looking for. Right now you might want a 14K or so but you might want to make stuff grow quick in the future and choose to lower it some or once its all grown out you can deepen the blue hue to make coral pop more. It gives you a lot more range of freedom. You can also put them on timers and have them turn on/off for a dawn/dusk effect this way. If you dont want this you can tie both into the same plug yet again saving a space on your powerstrip

[StevenSeas]

Would you recommend running the fixed current drivers instead?

I would deffinitely go dimmable. Makes light acclimating things easier. Also if you go with the wrong ma current then you will be outta luck. Cuz if its too high it will bleach everything too low and you get slowed growth.

[txg8gxp]

Not at all, dimming is awesome. Just with those drivers you just need to understand that w/o adjustment the output current is higher then what some leds can handle. Nothing wrong with constant current drivers, but dimmable drivers are really nice just more stuff to hook up. You will need to build/buy a variable 1-10vdc power supply to run the dimming function

[Zack]

Well the thing about getting two drivers is (at least what Mike said) that I need to have a minimum of 8 LEDs per driver. I want to run 12, I think 16 might be too high.

@txg8gxp What bulbs and what driver would you recommend? I don't want to blow the LEDs. By saying "w/o adjustment the output current is higher then what some leds can handle." would this be similar to running a 75 w halide bulb w/ a 150 w ballast?

Sorry, I don't know much about wiring and electricity..

Thanks for all your help!

[txg8gxp]

8 is just a safe number, the drivers runs 24-48v. So the minium led count would depend on the series of emitters. Different emitters have different foward voltage ratings. You also have the option of running dimmable buckpuck drivers. No extra power supplies needed for dimming and they run 3-6 emitters per driver. With the buckpucks you do need a 24vdc power supply to power the drivers though. The meanwells are AC to DC drivers, buckpucks are just DC.

[Zack]

Each "emitter" is the LED itself correct?

[txg8gxp]

Yes, emitter=led

[StevenSeas]

That and RapidLED doesnt carry buckpucks so he probably wouldnt mention this. But I have worked with Mike before and good guy and service. I am currently running 2 LED fixtures 1 with 2 meanwells and 1 with a buckpuck. It really comes down to how many you want to run in a string. But I that is a good point to bring up as it slipped my mind about the minimum number of LEDs due to the voltage output on the meanwells.

[Zack]

Would it be better for the LEDs to run a 16 LED system divided between two drivers then 12 on two drivers?

The LEDs are the XR series so I would be looking at 8 whites and 8 blues?

Also, did you guys build a case to put the LED unit in, or is the heatsink just above the tank?

[StevenSeas]

I would go with 16 and run them at a lower ma. this benefits from a few things. Less heat on the indiviudal emmitters, longer lifespan of the emitters, and better coverage. The one main weakness I see with LEDs is the lack of coverage per watt. so I would go with more at a lower current.

I would do 8 and 8, on seperate drivers so you could do what you want.

my 1st one is in my BC hood and so doesnt have a case.
my 2nd one is encapsulated and waterproofed and in my tank so that one doesnt count
but I would recommend that atleast you put either a acrylic or glass splash guard in front of the LEDs.

there are a ton of great LED builds on nano-reef so maybe you could look to see what others did with their 10 gallons.

[Zack]

Ok, after viewing many threads, this is a successful unit parts list I have found.

6 Cree Royal Blue XR-E LEDs
6 Cree Q5 Cool-White XR-E LEDs
2 1000mA Wired dimming w/ pot BuckPuck
1 24V 6.5A powersupply
1 16"x5.375" heatsink

Is a BuckPuck the same as the drivers from rapid LED? Also is the 24V 6.5A power supply what is plugged into a wall? If not how does the unit get power? Also how do you dim this unit?

[StevenSeas]

Ok, after viewing many threads, this is a successful unit parts list I have found.

6 Cree Royal Blue XR-E LEDs
6 Cree Q5 Cool-White XR-E LEDs
2 1000mA Wired dimming w/ pot BuckPuck
1 24V 6.5A powersupply
1 16"x5.375" heatsink

Is a BuckPuck the same as the drivers from rapid LED? Also is the 24V 6.5A power supply what is plugged into a wall? If not how does the unit get power? Also how do you dim this unit?

no RapidLED doesnt sell buckpucks. but they can be found http://ledsupply.com/03023-d-e-1000p.php
yes the power supply is plugged into the wall and they then are wired to the buckpucks. The dimming is with a "pot" or basically a knob that you turn and it dims the unit or lights it up more

[Zack]

Ok, with this pot, do I have to mark a set notch and basically NEVER turn it past this notch, or no matter what, that particular buck puck will not burn out the bulbs? Also, where does this pot connect to? is it outside of the hood, or do I have to open up the buckpuck to adjust it, like with the meanwell drivers, or is it visible on the unit?

[StevenSeas]

The pot comes wired to the buckpuck. You can splice into this and make the wiring harness longer to mount it to wherever you want. it looks like this
http://photoshipone.com/zencart/images/potentiometer.jpg
only the ones that come with it are smaller. Also the buckpuck only puts out a max of 1000ma and so therefore you shouldnt be able to burn out your LEDs unless you dont properly cool them. So you might want to mark where you keep them but no need to be afraid of passing the notch.

[Zack]

Ok, so that picture above comes with the buckpuck listed earlier?

[StevenSeas]

yes it looks like the picture below. the buckpuck is the black box and the pot is the blue&white thing and they come wired together
http://i932.photobucket.com/albums/ad161/aggiereefer12/Mobile%20Uploads/100MEDIA_IMAG0360-1.jpg

[Zack]

Sweet! Thanks man! I'm going to be go the two buckpuck route, thanks for your help!

[StevenSeas]

np if you have any other question I am willing to help as I am sure so will txg8gxp or any other maastards. OOO and make sure to document it and make a build thread so we can help and reference other people wanting to DIY LEDs to threads in our own forums.

[Zack]

Will do, might be a while, gonna do it around spring break possibly.