View Full Version : Moonlight

05-04-2004, 11:14 AM
ok, first off


And who has moonlights? Do u leave them on all night(is it safe)? Is there any other reason to have them besides that they look cool? Is there any metal halide equivalent that comes very small for my 10g nano? If I were to add moonlights and ran them with my pc, would you still be able to notice the shimmer effect? Basically tell me everything there is to know :D


05-04-2004, 11:32 AM
LED = Light Emitting Diode
CSL = Custom Sea Life

05-04-2004, 11:40 AM
wow, k, so CSL will not be an acronym I will need to remember.

Sir David
05-04-2004, 12:02 PM
I have LED moon lights that I leave on 27 x 7. They are so dim that you cannot see them if the tank lights are on. I have them because they look cool but there is some evidence that they can effect coral growth. Sean D knows much more about it than I.

Oh yeah LED = Light Emitting Diode They are dim bulbs used mostly for accents.
CLS = ???

Here are some links that helped me
http://reefcentral.com/forums/showthrea ... genumber=1 (http://reefcentral.com/forums/showthread.php?s=&threadid=205488&perpage=25&pagenumber=1)

Search the DIY forums of reef cental or nano-reef.com for more help and ideas.

05-04-2004, 12:12 PM
I also leave my led moonlights on 24/7. As far as I know they are supposed to help the corals in growth and reproduction?

05-04-2004, 12:23 PM
I think I'm going to build one like on http://www.kaotica.com/frag/diy/moonlight/

If anyone else is interested maybe we could get together and make a few of them.

05-04-2004, 12:56 PM
The LEDs are $22 for 15 of them... I'd only use maybe 4 - 6. Is anyone interested?

05-04-2004, 01:03 PM
kaotica.com even has a forum for discussing the led moonlight design.

Some guy wired 3 into a 10 gallon nano.

05-04-2004, 01:04 PM
I wouldn't use many, but I'll get in on that.

05-04-2004, 01:10 PM
Sean D knows much more about it than I.

I'm not quite that well versed in LED technology, but I have been reading up a bit lately.

I personally have a Solar 100 LW dimmer/controller from Blueline (Champion Lighting sells them) controlling a 25W blue barty bulb. Ideally, I'd get a light that emits near 470-475 nm (which is supposodly what moonlight is). There are LED's at 465-470 nm, which is pretty close. My Solar 1000 will control up to 150W of moonlight. Supposodly teh new ones will do 300W.

I have no real evidence, but my feeling is that corals will be better off with a moonlight simulation that actually mimmics the phases of the moon. Moonlight changes intensity on a regular cycle, but it's also out at all different times of day and night.

I was going to look into the blue LED ropelights for my big tank. Supposodly you can dim them straight from an AC plug. There's another issue that LEDs do not dim in a linear relation to applied wattage (like incandescent), but I'm willing to overlook that since LEDs are so much more efficient than incandescent blue party bulbs, and although not linear, it's still close.

The 25W bulb I'm using is barely enough for 1/2 of my 200 gallon. I'd need more like 200W worth to really work in my 400. Plus, I want to use the same controller for the 180 refugium. That tank will be on a reverse daylight schedule from the main tank, but probably the same moon schedule. If I can use the LED ropelights, I should be well under the 150 watts that the dimmer can handle.

I've also been looking into dimmable Cold Cathode tubes (funky automotive and gamer PC lights). One other option is getting an old color LCD panel from a laptop and programming it to simulate the moonphases and use a pallate to get the color correct... That would actually be a pretty cool idea. You could just make 28 different images (actually, you could probably get by with 14) to simulate the moonphases. Tweak the color and brightness, and then write a windows macro to cycle thru them as a screen saver. Mount the screen in the top of your canopy... Hmmm. I may try that. Anyone have an old 386 color laptop?

Another option is to Get X-10 firecracker for your PC and get the X-10 dimmable lamp module. Then program a macro to control it (there's an existing freeware one out there). Of course, then you're using X-10, which may not be compatible with other electronic equipment in your house (e-ballasts, home theater equip, ethernet over opwer lines, etc...)

05-04-2004, 01:17 PM
I think I'm going to buy 15 of these LEDs for $1.77 each (including shipping. I will probably us 5 in my main tank, and 2 or 3 in my nano. Is anyone other than Dolfan interested in what I have left? Or if more people are interested should I place a larger order?

Sir David
05-04-2004, 01:22 PM
Sean D knows much more about it than I.

I rest my case.

05-04-2004, 01:42 PM
I think I'm going to buy 15 of these LEDs for $1.77 each (including shipping. I will probably us 5 in my main tank, and 2 or 3 in my nano. Is anyone other than Dolfan interested in what I have left? Or if more people are interested should I place a larger order?

I am interested, but don't know if 7 or 8 will be enough for my tank. I have about 7' of length to cover. My tank has two lid ribs along its length so I guess I could put two on each end and two in each lid rib for 8. Would that work for your needed quantities?


05-04-2004, 01:46 PM
I can buy 15 as a sample pack, or I have to order 30.

I guess we can see if there's any further interest. If you want 8, (but it sounds like you need more) let's see

Me 7-9
DolFan 2-4(?)
Mitch 8+

If we can get 1 or 2 more people to be interested I can just order 30.

05-04-2004, 01:49 PM
I'll watch the thread and see how things shake out. I would definitely be interested in a group fabrication day. Beer, electricity and lots of salt water; sounds like my kind of fun.


Sir David
05-04-2004, 01:50 PM
I did not want the spotlight effect that some of the picture show so I added a few more led's and pointed them up into the reflector in the hood. It gives a nice, soft, diffused light.

I used I think 6 on my 65 (3 feet long) so you may want more bulbs than that Mitch.

05-04-2004, 01:54 PM
You're probably right. If I used the lid ribs for mounting, I would be at either 12 or 16 total. My concern would be how "banded" the light would be mounting them at 0-33-66-100% along the tank length.


05-04-2004, 01:56 PM
Beer + Electricity + Water = ???

:lol: :lol: :lol:

05-04-2004, 01:56 PM
yeah I'm not sure what exactly causes the shimmer effect with these or the halides, but if u were to turn them around would that eliminate that effect? I dunno, I'll play with them till it works :D

05-04-2004, 02:00 PM
I was thinking of maybe mounting mine on maybe ˝" pvc tubing, or something like that. Does anyone know what heat shrink tubing is? It would add a certain level of waterproofness and would make it a stable structure. For my nano I'll probably just drill holes in the hood and mount them. I'm thinking Jeremy may get in on this since he is an equipment junkie.

Jeremy E
05-04-2004, 02:06 PM
Alright I getting in. Put me down for 10 of them I will try it. Heatshrink is sold at the depot in the receptacle isle. We will need it. Put the wires throught pvc painted black and shove or thread the leds in. heat shrink the wires to a plug with a timer and we're set! Let's do it. heck I am going to paint the pvc black even. What do you think?

Sir David
05-04-2004, 02:07 PM
I used some of the clear corner bead used to protect wallpapered walls to mount my lights. I was cheap and easy.

05-04-2004, 02:08 PM
Sounds good. Looks like we have enough interest for 30 of these... I'll until tomorrow until I actually order since not everyone trolls this board all day long.

I'm free next Saturday and Sunday... everyone else let me know.

Sir David
05-04-2004, 02:09 PM
Jeremy, don't forget the resistors. You will get much shorter led life without them.

05-04-2004, 02:09 PM
I have a crazyass acrylic hood on my bowfront so I have absolutely nothing to mount to. I figured I could make a cheap, quick, and easy "H" out of pvc to mount them in, then just lay it on top of my tank inside my canopy.

Jeremy E
05-04-2004, 02:14 PM
Dave I have scrap acrylic we can use to mount them in. What yeah think?

05-04-2004, 02:20 PM
The pvc would make them a little more water resistant, too.

At least that was my thought.

05-04-2004, 02:29 PM
This has really turned from a "General Discussion" thread into a "DIY" thread....

05-04-2004, 02:35 PM
ya I'm glad I could start a lively conversation. I hate starin at that board all day with no new posts :D , this is turning into a chatroom.

Sir David
05-04-2004, 02:43 PM
Egg crate might work too.

05-04-2004, 02:51 PM
I have 8 LED's on my 125 gallon and they look great. I used the corner piece like Sir David is talking about. Remember your not trying to light the whole tank.

05-04-2004, 03:05 PM
That PVC sold for direct bury electrical conduit is already a nice dark gray. No need to paint. Are you sure we're still at 30 lights? :P


05-04-2004, 03:34 PM
Once we get at least 30 lights we can buy them in whatever quanity we want. The way the ordering works is 15, or 30+

05-04-2004, 03:36 PM

Just to be safe though please post how many lights you would like by tomorrow at 3 o'clock and I will order them.


DaveMac - 8

The lights will be $1.42 each plus $5.35/(number of people) for shipping.

05-04-2004, 03:37 PM
Me - 4 Please

05-04-2004, 03:40 PM
Batfish - 16

Sir David
05-04-2004, 05:41 PM
I recommend having a spare or two. It is possible to fry them in the soldering process.

05-04-2004, 05:54 PM
yeah I'm not sure what exactly causes the shimmer effect with these or the halides, but if u were to turn them around would that eliminate that effect? I dunno, I'll play with them till it works :D

Shimmer lines are created by a point source of light being focued by surface agitation of the water. As a wave goes by and intersects other waves, it basically creates a lens. I'm not sure if the crest or trough of the wave is the part that focuses the light, but one of them does.

Think of it like you had a bunch of magnifying glasses floating on your water and moving around. The more surfave agitation, the more lenses.

Flourescent tubes will cause a similar, but much less noticable effect. You can usually see it in the top 2" of water along the back of the tank with a lot of surface agitation. It's more like linear bands (aruora borialis-ish) than interwoven glimmer lines.


Here's a place with the AC powered and dimmable LED ropelights. You hav eto order at least 30 ft at $6.25/ft and then also get the endcap and AC adapter.


05-05-2004, 08:04 AM
Currently, we're at 40 LEDs, (I decided to get 10, just in case)

Any more takers?

Jeremy E
05-05-2004, 08:08 AM
You know I bet those led's will really spur up Corals such as xenia whom tend to grow fast anyways and get multiple stalks and claspings hands fast since they breed so quickly. Can't wait to find out.

Dave put me down for 15 total...

05-05-2004, 08:41 AM
That will put at at 45.

So far I have:

Myself - 10
Dolfan - 4
Batfish - 16
JeremyE - 15

Anyone else?

If not the total will be (bulbs*$1.42) + $1.34

I'll give everyone else until 3, until I order.

05-05-2004, 08:51 AM
I've been reading and it looks like it will be easier if Dolfan, JeremyE, Batfish, and I all get together and do this as a group and use the same exact equipment. I've been in contact with this DIY guy and he gave me all of the info. I am pretty sure we should buy this transformer:

http://www.radioshack.com/product.asp?c ... 273%2D1662 (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F009%5F001%5F001%5F002&product%5Fid=273%2D1662)

Then we will need 45 140-150ohm resistors from Radioshack, and some speaker wire, (according to the nifty program he supplied me) which are 5 for $1 at radio shack.

The only other thing we will need is a 30W or less soldering iron. I have one, but am not sure if it is 30W or less.

Let me know if you want to get together and do this as a group. I'm free all next weekend, and would love to host a moonlight DIY party, but be forewarned that it is the weekend of the Trenton yard sales and my city will be overrun with yokels.

05-05-2004, 10:03 AM
I'm up for it. You are talking the 5/15-17 weekend, right? Can you share that program the DIY guy gave you or provide a link? I would like to see how it determines the voltage and resistance values. Everyone is welcome at my place in West Chester if you don't want to brave the Trenton yard sale mob. We just went through that 2 weeks ago and it was a mess. I have a Rat Shack about 2 miles from my house.


05-05-2004, 10:18 AM
My closest Radio Shack is about 20 minutes away, so if Mitch doesn't mind having us over, that may be a little better.

Here is the link for the program that calculates the resistor needed:


I based my measurements on the previously posted link for the Radio Shack transformer set to 6w.

Yes, 5/15 or 5/16 will work as long as the LEDs are delivered by by then, (there's no reason they shouldn't be.)

Mitch, I hope you wife doesn't kill you for having your reef geek friends over 2 weeks in a row!


05-05-2004, 10:33 AM
Nah, she won't mind. We'll stay out in the workshop where we can make a big mess if need be. Just let us know if the LEDs look like they'll be here on time. I would vote for Saturday morning to do the deed if that will work for everyone else.


05-05-2004, 10:37 AM
What's "morning"? :shock:

05-05-2004, 10:42 AM
That's why I didn't post a time. People differ in their opinions of "morning". I would think starting around 10AM is reasonable. Is that too early/late?

05-05-2004, 10:44 AM
I could prolly do that, as long as we're goin to your house, Davemac's like 20 more minutes away *lazy* :D

05-05-2004, 10:45 AM
I posted directions to my place in the May Meeting thread. If you are coming from Mason, you're best off just taking Hamilton-Mason Rd to get there.


05-05-2004, 11:03 AM
The only reason they wouldn't arrive in thime is if they're out of stock or something. They are being shipped UPS ground.

05-05-2004, 11:48 AM
could we make it 5/16? I have to be at home Sat from like 11am-3pm waiting for the Roadrunner guy. Had to make this appt. like 3 weeks in advance :x , stupid people don't do this in the evening...when everyone is available.

05-05-2004, 11:49 AM
Doesn't matter to me... Saturday or Sunday, morning or afternoon or evening. Jeremy needs to let us know what his schedule looks like, too.

Sir David
05-05-2004, 01:09 PM
You need to match the resistors to the specific power supply you are using. Better figure on going to radio shack sometime. Go to h ttp://www.electronics2000.co.uk/calc/calcled.htm to get a calculator

05-05-2004, 01:13 PM

05-05-2004, 01:14 PM
Yeah, that's what the download link was about 10 posts ago.

05-05-2004, 01:23 PM
If someone wouldn't mind checking me I think the attached image numbers are correct based on the data sheet located here:


According to this we should use a 120Ohm resistor with a 6w power supply.

If my calculations are correct when we hit 88 miles per hour you're going to see some serious :censored:

05-05-2004, 01:28 PM
From the LED source's website they state:

For optimal colorization and intensity (5.5+ cd), forward voltage of 3.3V is recommended.
I'm guessing that changes things a bit.
Also, how are you taking into account the voltage drop at each LED? If I put 16 in series and someone else puts 4, we will need entirely different source voltages and resistors will we not?

05-05-2004, 01:34 PM
I was wondering about that... I sent the author an email.

Are there any members that are electrical engineers?

I have a friend that is a journeyman, I will ask him tonight.

05-05-2004, 01:47 PM
For the curious:


05-05-2004, 02:00 PM
http://www.thesea.org has several good articles on this from when this guy was trying to figure this out at first. Here's what I picked out:

"Lets work this out here. With a 6V supply and all the LED's in Parallel you have 6V across each LED/resistor pair. You want only 3.3V across the LED so you need to drop 2.7V across the resistor and pass 20ma so R=E/I, R=2.7/0.02
so R=135ohms

For 9V you need to drop 5.7V across the resistor so R=5.7/0.02 so R=285ohms

In actual practice you will never find resistors of these values so pick a standard value that is within about =/- 10% 150ohms and 270ohms are fairly common and will work just fine. "

"If you're wiring in parallel (like drawn), you can wire each one like you have just like you would wire one of them. The voltage across each one will be the same as if you wired a singleton. "

need some electronics help (resistor values)

DIY Moonlight w/ LEDs
http://www.thesea.org/phpBB2_viewtopic. ... sc&start=0 (http://www.thesea.org/phpBB2_viewtopic.html?t=2789&postdays=0&postorder=asc&start=0)

a request for moonlight users

05-05-2004, 02:47 PM
Here’s my schematic. Sorry for the crudeness but I didn’t have time to draw it to scale.

Warning: 1.78Mb


05-05-2004, 02:51 PM

One of these articles mentioned liquid electrical tape. Paint it on and it dries to a flexible plastic....looks kinda like the stuff they dip the handles of pliers into, only its black.

Do you guys have something like this?

05-05-2004, 03:18 PM
I ordered the bulbs and split up the shipping:

JeremyE = $22.64
Batfish = $24.06
DolFan = $7.02

I'll let you know as soon as they arrive. The confirmation page said my order will be processed and shipped within the next few days... whatever that means.

05-05-2004, 04:12 PM
I can Paypal you the funds if you need them immediately. Just let me know. And thanks for doing the order. This should be a fun project.

05-05-2004, 04:15 PM
No, I put it on a credit card, so whenever we end up doing it will be fine.

05-06-2004, 07:57 AM
The bulbs are shipping out today via ups.

I talked to my electrician friend, and I guess this is more of an electronic problem, and he wasn't very helpful. The one thing he did say was to wire it all up and test it with a voltimeter. That would be fine, but I don't want to have to rework the design when we're all together doing this.

I did decide to post the question on ReefCentral

http://reefcentral.com/forums/showthrea ... did=368317 (http://reefcentral.com/forums/showthread.php?s=&threadid=368317)

And I have 1 more person I can ask.

05-06-2004, 08:31 AM
I found the calculations we need to figure this out. The last calculator on the page:


If LEDs are wired in a series the voltage drops, but if they're wired parallel the current drops. Hence the more LEDs you have the smaller resistor you need to use.

05-06-2004, 11:28 AM
The above link assumed that you use one resistor for the entire thing, so it does not apply to what we are doing. I was correct in thinking that you use 1 resistor per LED and the voltage will not drop whether you have 2 LEDs or 15. I verified all this with a UC professor who thought I was a former student of his in the electrical engineering school.


05-06-2004, 11:36 AM
This is from Professor Narayan from Miami University:

6 Volts are supplied.
You need only 3.3 volts across LED.
2.7 Volts should be lost in resistor.
LED can drain 20 mA.

Resistor Required = Voltage Across Resistor / current

R = 2.7 Volts / 0.020 Ampere = 135 Ohms.

Wattage Required = Volts * Amps = 2.7 * 0.02 = 0.054 Watts.

To be on the "safe side" use a Factor of Safety of 2.

Wattage Recommended = 2(0.054) = 0.108 watts.

Select a 1/8 Watt resistor (0.125 Watts ..... Normally manufactured.)

You may not be able to find a 135 Ohm resistor. Use 150 Ohms instead.
(Anything larger than 135 Ohms)

Final Design, assuming I read the problem correctly.

150 Ohms, 1/8 Watt Resistors in series with EACH LED.

Hope this helps.


I spoke with him on the phone and he said the only thing you will lose with a parallel connection is mA. Since each LED need 20, and the transformer is 300mA you can power 15 LEDs before you start to lose intensity.

I think we have this all worked out. Now we just each need a transformer, 45 150w resistors, and some wire.

05-06-2004, 12:04 PM
I wonder if I could find 6v, 300mA transformers at someplace like Trader's World? Anyone else have a suggestion where I could find cheaper ones?

05-06-2004, 02:31 PM
I found 6v 500mA AC/DC power adapters for $4.44 including tax. Is everyone in for one of these?

05-06-2004, 02:33 PM
whatever u think is best :D

Jeremy E
05-06-2004, 02:48 PM
Put me in for the adapters and resistors as well and give me the total. Liquid electrical I wiil check. I am sure we do as I think it's in a yellow can but I am not sure. Will check. Jeremy

05-06-2004, 02:54 PM
I found 6v 500mA AC/DC power adapters for $4.44 including tax. Is everyone in for one of these?

I'm in. Though I probably have 2 or 3 of these laying around, it's easier to pay this than go through all those boxes.

If you guys are sold on this liquid electrical tape, we'll do it. If you are still on the fence, I can get a buttload of shrink tubing and a heat gun for free here at work.

05-06-2004, 03:00 PM
Whatever works. I can across a 30w soldering iron we used to use for circuit boards and a voltimeter (with a blown fuse). All we should need is wire and liquid tape/shrink wrap.

I figured all of us using the same adapter would be better because we could use the same resistors.

Liquid Electrical Tape?
It doesn't matter to me Mitch. How much is that stuff anyway, Jeremy? If it's cheap I'd like to try that... it sounds cool.

I'm getting the adapters from a electronics company in Franklin. I didn't think to ask, but I'm sure they sell resistors, too.

05-06-2004, 03:05 PM
I've got a couple of soldering irons, too. I don't know what wattage they are, but one's a real hoss; probably too much for LEDs. The other one is more a delicate work iron. I've also got a bunch of solder and one of those little clamping stands so you don't burn your fingers.

Just a thought: Doesn't Rat Shack sell little plastic clamping collars for LED's that allow you to snap them into drilled holes? That might be an option for some of us depending on tank setup.

05-06-2004, 03:17 PM
I was just going to drill a hole in pvc pipe and snap it in. I didn't realize you needed a collar. I guess if they have them we'll need some of those, too.

05-06-2004, 03:21 PM
I may be mistaken, but I don't think LEDs will "snap" by themselves. They have a bullet nose, a cylindrical body and little square molded lip at their base. You could put them through a drilled hole, but would need to secure them with hotmelt or something similar.

05-06-2004, 03:23 PM
Jeremy, are you going to be free next Saturday? (or Sunday, whenever we decided we are doing this)

150ohm resistors are 20/$1.20 at this place which beats Radio Shack's rape-job of 5/$1

I guess I'll get 3 bags and if we have any left we can just have some "fun with electricity"

05-06-2004, 03:43 PM
Sunday! :D Or Saturday but later(after 3pm)

05-07-2004, 08:13 AM
Sooner or later, someone had to say it...

05-10-2004, 10:02 AM
The LEDs were shipped via priority mail on Saturday. Should get them today or tomorrow.

05-10-2004, 10:05 AM
Let's nail down the "when". I can be pretty flexible so you guys let me know when it works best.

Jeremy E
05-10-2004, 12:20 PM
Anytime after 7pm on either saturday or sunday will work for me. How's that? I work retail so I don't have a normal job like everyone else.

05-10-2004, 12:28 PM
Either Saturday or Sunday evening will work for me, too. I think Dolfan was fine with anything after 3 o'clock. What about you, Mitch?

05-10-2004, 02:49 PM
I vote for after 7PM Saturday in case we stay up too late. Need my beauty rest for work on Monday!

05-10-2004, 03:00 PM
Okay, it looks like sometime between 7 - 8 at Mitch's on Saturday.

I'll be bringing: transformers, (not the robots in disguise kind) resistors, LEDs, a solsering iron, and a Volt-Ohm meter (if I can find a replacement fuse for it)

We will need wire, solder, and tape/shrink wrap.

See everyone there!

05-10-2004, 03:09 PM
I will have a soldering iron, solder, soldering stand, multimeter and I can get shrink tube and wire. I assume you want stranded stuff in the 14-16 gauge range? I have a spool of speaker wire, but don't know how much is left. There is also several miles of wire here at work, but I will have to check and see what all we have.

For heavy power tools I have: drill press, chop saw, radial arm saw, table saw, grinder, router table. I also have a good selection of hand tools and lots of hammers. :badgrin:

05-10-2004, 03:20 PM
Allrighty \:D/

05-11-2004, 01:45 PM
Here's my ghetto design for a moonlight holder:



Since my canopy is acrylic, stapling the lights in place wasn't an option. I used ˝" PVC to construct a holder for the lights and place them in the tank. In retrospect, I guess it would have been a good idea to take a picture with the fixture actually on the tank ( :idea: ) but oh well.

I notched the end of the PVC elbows so they fit snuggly onto the tank molding:



I spent about an hour in Depot's plumbing section (with no help from JeremyE) trying to figure out a way to fit the bulbs so they could rotate. The only thing I came up with was to place a "T" where I wanted a bulb and have the light shine out of the open end. I made this fitting with 4 bulbs, 2 on each side, and an opening in the middle for the wire. I initially was going to do 6 bulbs, (shaping the fixture like the letter "H"), but I decided to wait and see what 4 looks like. If I decide to add 2 more (like my original design) I can add another piece of PVC to this with no problems.

Jeremy E
05-11-2004, 03:27 PM
Yep that's as ghetto as it gets! :D Could have at least painted it. If I was there I still wouldn't have helped you! :badgrin: Don't have that much Ghetto in me. :lol:

05-12-2004, 11:38 PM
The LEDs came in today. If I get a chance tomorrow or Friday I may do a test assembly for my nano. I plan on only using 1 LED for it so it should be pretty easy and straight forward. If you don't hear from me in a couple of days start checking the obits.


The LEDs do not come with sleeves, so I guess we'll have to get those from radio shack. Are we still on for Saturday at 7?

05-13-2004, 08:20 AM
Works for me :D

05-13-2004, 08:30 AM
I am still go for 7. You guys want to do pizza or will your bellies be full on arrival?

05-13-2004, 08:32 AM
I'm down for whatever \:D/

05-13-2004, 10:58 AM
Hey guys, I just remembered where I posted this before. This might save you some resistors and soldering. :D

Below is the formula I used to get the resistance for a number of LEDs in parallel and using 1 resistor on one leg of the parallel circuit to run all of the LEDs. This way you don't have to wire a resistor in series with each LED. Everything worked great tonight putting them together (Pictures Later) but I need a resistor that has a higher power handling rating. The little 1/2 watt resistor I used got really hot. Hot enough to make water sizzle off you fingers or burn them. I put 7 LEDs in the circuit so it's total amperage is 140mA. That works out to about 3/4 of a watt at 5v.

Pretty Sure this is right and seems to work fine. I'm not the best at this stuff some times, but here it goes.

X = # of leds
V = The required Voltage of your LEDs
Y = The mA rating of your LEDs
Z = The resistance of the LEDs
P = Power Supply Voltage

V / Y = Z
X x Y = A
P / A = B
Z / X = C
B - C = Required Resistance

05-13-2004, 11:51 PM
Since I'm the guy who somewhat spearheaded this, and since I have $80 worth of equipment for our project in my garage I decided to do a test.

Instead of the blind leading the blind and all of us ending up with burnt up transformers or blown bulbs I decided to be the guinea pig.

I cut the end off of the transformer and assumed that the wire with the white stripe was the hot one. I used 16g speaaker wire and 2 butt-connectors to wire the transformer to the speaker wire. Since I don't have solder, (do you need special solder? I have a 30w circuit board soldering iron, but will it melt normal solder, and will normal solder work on LEDs?) I used a rednecks best friend, electrical tape. I taped the hot to the resistor (brown end first) then the resistor to the long LED cathode. Then I taped the other cathode to the remaining wire.

I was pretty nervous about this, so I got a surge protector and pluged in the trandformer. THEN I plugged the surge protector into the wall. THEN I flipped the switch, and.....




I was so proud of myself that it worked. I decided to see how bright it was by looking into it, and now 5 minutes I can still see a dot… it was that bright. So I decided to put it over my tank and take a look… NICE! So I took it upstairs to my nano, (I was wondering if 1 was enough, anyway,) all I can say is awesome, awesome, awesome.

I took my “test” apart, and we’ll be ready to go Saturday. After this experiment is over I am going to write an article much like the one we are following, but make it much more detailed including part numbers, bulb numbers, and resistor calculation so anyone could easily follow in our footsteps.

I can’t wait until Sat!

05-14-2004, 08:15 AM
ACK! the pics didn't work! :shock: , but it sounds like it worked so that's good :D

05-14-2004, 08:29 AM
There were no pics....

:badgrin: :badgrin: :badgrin:

Just a huge gap to leave everyone in suspense to if it worked or not.

05-14-2004, 09:02 AM
lol, worked! :eyecrazy:

05-15-2004, 09:51 AM
LED Holder FYI

I went to radio shack yesterday, and picked up a pack of the plastic led holders 5/$1.29. The also had metal ones that looked a lot nicer, and had places for the cathodes, but they were 2/$1.29, so I bought the plastic ones.

Long story short, I broke 2 leds because the cathodes broke off while I was trying to manuver the wire and in hindsight I wish I would've bought the metal ones. I am going to pick up 2 packs of metal ones for myself today, and the 3 remaining plastic ones are anyone who wants them.

Are any of you even mounting your lights in a fixture, or are you just suspending them in the canopy? If you're just suspending them you wouldn't need these anyway.

05-15-2004, 12:46 PM
You guys didn't say if you wanted to order some pizza or not. If not, I will make sure to be done with dinner before you guys arrive.

05-15-2004, 01:44 PM
I'd be down with pizza...whatever u guys wanna do. I'm out, if I need to know anything else I'll get it from Davemac, so hopefully he'll hear about it :D

05-17-2004, 09:06 AM
Just wanted to publicly thank Davemac for doing all the research and ordering the parts. After a slow start we finally got into gear and had my admittedly ghetto moonlights mounted around 1AM. Things looked so good that we drank beer and watched the tank for another hour. Dave had his super hi-tech version all wired up and ready to mount. Tony and Jeremy left with a mission and the method.

It was a big success all around. We drank lots of beer, ate three large pizzas, talked reef, burned ourselves, and forever did away with me having to shine a flashlight into the tank.

05-17-2004, 09:14 AM
Yeah it was a good time. I'd like to thank Mitch for being the glue that held this project together. Without him we would've just been 3 clueless, drunk guys planing with electricity.