ok, sounds like a 1' by 7.5" wide heatsink will be good. i understand tapping th holes to fasten the led's to the heatsink, and you wire them after they are attached to the heatsink, but what is the purpuse of the thermal epoxy? i also need some help in figuring out how to hook up the leds to the buckpucks and the powersupply, and how the dimmer's on the buckpucks are used(external knob? or something electronic)

You don't want to use thermal epoxy, just a thermal grease. It provides a better thermal interface between the pcb and the heatsink. The grease is not permanent like the epoxy. Arctic Silver 5 works really well.

All that you should need to know about the Buckpucks and how to connect to them is detailed here

http://www.leddynamics.com/LuxDrive/datash...21-BuckPuck.pdf

so you apply this before you fasten the led's to the heatsink to promote conduction? also what is the deal with polishing the heatsink? i am quickly figuring out how to wire the led's together, but is there a diagram of what else to wire where? (buckpucks, powersupply, potentometer, etc). i am a sophmore in highschool and i am still a little slow on electronics, but if i have a little more ifo i can figure it out...

here is a list f equipment that i think i need for the project, can you look and see if i am missing anything?

12 cree cool white leds
10 cree royal blue(700 ma)
2 uv led's( any good brand?) ( run on same buckpuck as blue)

heatsink (1'x7ish inches)

power supply

externally dimmable buckpucks ( how many?)

project box

thermal paste

threaded wire

solder

silentx fans

screws

washers

heatshrink tubing

tap kit

power cord for power supply

Your list looks pretty good. For 24 LEDs, you will need 4 Buckpucks (max 6 LEDs per). Get the 3023-D-E-XXXP versions (replace XXX with the desired drive current). These come with the pots already connected, so you just need to wire the LEDs and the power supply.

3W UV LEDs are only available from Kai Domain. Just search for "3W UV" on the site.

The datasheet shows you how to hook everything up. Look at page 6, figure 8. Just add three more LEDs. the label on the top of the driver will tell you exactly what to connect to each wire. Read around at some of the build threads around here too. There is a ton of information here.

so the buckpucks will ave the dimming attachment already attaches, so could i just drill a few holes on the hood of my pod and have the dimmers serve as switches?

the dimensions of the iside of the splashguard are 16.5 long by just under 6 inches deep. tha tis only under the perfectly clear part. i would then go with the small 12" plus heatsink , which i would have made 16" by 5.35 wide (standard)

are there optics for the kai uv's?

Don't need them. You want as much spread on those as you can.

ok. sounds good. is it possible to have the entire system in the hood of the aquapod? saw one thread where the guy had the pots sticking out of the top of the hood so he could dim the tank as needed. i could easily see getting the buckpucks to fit, but will the power supply and other components also fit? are there any additional controls for on/off, or do the dimmers cover that too?

also will upgraded fans that are in the stock position be enough to cool the heatsink or will i also need a fan on top of the heatsink? im not sure a fan will fit on top, which is why i ask.

Well ive got the buch pucks and the leds ordered. they are on their way now. the pucks cost me $36. There was a minimum fee of 100 bucks for the leds. I ended up ordering some lenses to and got the total up to $90. they went ahead and let it through. I didnt think i needed the lenses for such a small tank but since i needed to up the cost i went ahead and got the 40 degree lense. Is that the right linse for a tank with these dimentions (16 L x 7.5 D x 14.5 H). I am already going over my budget so i was trying to think of a way to save money. thats where the power supply comes in. The buck pucks suggested input is 24v. I happen to have two or three 12v power supply lying around. would it work just as well to use two 12v instead of one 24v.

should i go with a 16x6( small) heatsink or a 16x7.5? ( med) some of the 7.5 might be under the less transparent part of the splashguard (up to 1.5 inches) but is this a problem if i space the led's properly?

Dimmers are just to dim. You will use timers like every other light to turn them on and off. You won't be able to put the power supply in the hood for two reasons. First, it physically won't fit. Second, it's not sealed and it will corrode.

Fans in the stock position aren't much use. They just don't provide flow in the right areas. Use a large 80mm or 120mm fan directly above the heatsink blowing on it. Thin profile fans (80x80x15mm) will fit between the heatsink and the hood.



40 degree lenses aren't going to be much use to you. If you can call and change the order, 80 degrees would be more useful if you decide to use them (you shouldn't need to). It will give a little bump in ouput, but won't kill your coverage, and won't burn your corals.

You could use the two 12v supplies, but you have to wire them in series to get 24v out of them. If I were you, I would just belly up and get a 24v power supply.



Cram the biggest heatsink you can fit. If the heatsink is bigger than the usable area, it does no harm, but it will allow you to place the LEDs where they need to be. More heatsink = better cooling capacity.

can you give me a link or two for some very quiet 80x80x15 fans? havent been able to find any yet...

http://www.newegg.com/Product/Product.aspx...N82E16835226001

Should i just forget the lenses completely and just buy a couple extra leds. Also would you suggest buying a thin sheet of plexi glass to incase the unit. thanks again for all the help.

thanks for the link. since the leds are turned on with timers, is it possible to have each buckpuck set up so you can have each set of 6 led's turn on in sequence for dawn/dusk? im not saying a gradual ramp up, just a 4 stage on/off process. i would like to be able to do this on one power supply, if possible

it is possible but you need a PS for each string then. best to use two, one for blues and one for whites.

Thats up to you. A few spare LEDs and a few lenses for experimenting with might be a good alternative.

A splash guard of any type will be highly recommended. When the array cools, it attracts condensation which will corrode metals. The splash guard stops that.

ok i think i am getting the hang of how to start this project but i do not understand what the dc cord is used for in this thread: http://www.nano-reef.com/forums/index.php?showtopic=189985

since you hook up a regular power cord to the power supply, and hook up the buckpuck's v- and v+ cords to the power supply also, what is the purpose of the dc cord and where is it used. the wiring diagram on page 4 of that thread was very helpful, but the dc cord is still unclear to me

hope im not too much of a bother, just making sure i know what is going on before i commit to starting the project

You are going to have to be more specific. If there is something in a particular post that you are looking at, either list the post number, or click the post number at the top corner of the post and paste the link it gives you.

It depends on how the power supplies are wired internally but it is generally a bad idea to put power supplies in series. If either or both of the output grounds are connected/referenced to the house ground wire then it can short out one of the supplies to put them in series and plug them both in. It might work just fine but it also might blow fuses, cause some smoke etc.

There are cheap 24v supplies that would be a much better choice, such as this one: http://www.mpja.com/prodinfo.asp?number=16854+PS .

I just ran through that thread and it appears as though he ran the 24v side of the power supply to 4 individual jacks, and then hooked the buck pucks to the wires+plugs that mate to the jacks. It is electrically the same connection as hooking up the puck wires directly to the screw terminals on the power supply, he just did it that way to contain everything to a neat pluggable box.

here is the post number: http://www.nano-reef.com/forums/index.php?...t&p=2150930

sorry i am such a burden...

i would like this well contained in the hood, excluding the power supply

I decided to just get a couple extra leds and im going to order the 24v power supply. you have been a huge help. Once i get my supplies ill probably start a new thread that will show my tank and all its mods. Lighting isnt the only thing ive messed with on that tank. You"ll have to check it out when its up.

There you go

ok, thanks so much! that tmakes sense. so if i was going to build a project box like his, i would have the buckpucks inside, attached to the female dc jacks, and have the dc plugs wired to the power supply and the power supply plugged into the wall? this way i could have holes drilled in the back of the hood to allow for easy disconnect of the power supply, to maintain the fixture. am i understanding thise concept correctly?

You could just mount the pucks inside the hood and have a single jack for the 24v DC power from the power supply. Try and keep te Buckpucks in the open. They seem to have an issues with overheating in tight enclosed areas.

ok, i should have all of the buckpucks wired to a single dc jack(protruding from the hood) and have a dc plug wired to the power supply connected to it. that would be great. i would have all of th buckpuck = and minus wires linked together accordingly for this, correct? i also saw that the dc jack is three prong, with a ne, neutral, and hot, but htere are only two optiions on a buckpuck. skip the neutral?

also in post 121 of this thread: http://www.nano-reef.com/forums/index.php?...t&p=2259380 it is mentioned that dc hooked to high currents can be dangerous if hooked up improperly, and since i tend so spill a little water when i do mantenance, i am concerned about exactly how to properly wire these things so this does not happen.

Which DC jack are you using? A lot of them have 3 terminals and one is a switched terminal that is connected to the positive when there is no plug, but when you insert a plug it becomes connected to nothing. It is usually best to plug the power supply into the wall and connect just the bare jack onto the power supply plug and then test with a multimeter to find out exactly which terminals are the + and -.

Nevermind that post about it being dangerous, as long as you are just running 24v DC through the barrel style jacks it isn't a problem. He has either changed the way he had it or I misinterpreted one of the pictures but I though he had the full 120v wall current going through one of those plugs. 24v and under generally can't do much to a healthy person which is why there is a big difference between normal AC and DC cables; you don't really need to worry about the 24v side.

ok that makes sense. so you would wire the buckpuck wires to the respective + and minus terminals on the barrle jack, and wire the dc plug to the power supply, right? the power supply then connects to the wall.

Today take some PAR reading from my existing 250w MH.
The bulb is Hamilton Tech 14k, 250 w
Below is the reading I get from my newly acquire Apogee Quantam Flux
Setting is Sun

Par Reading

Depth * MH(250W)
4 IN. 200 - 340
5 IN 185 - 280
6 IN 180 - 270
8 IN 150 - 218


NB.: Light is 4 inch from water top
* From water top

MH reading is taken where the reading is the strongest.
That is within the light enclosure

What kind of reflector was used?

Its a normal reflector found on most commerical MH light set

Hmm. Seems a little low from my experiences with taking PAR readings.

I'll take some measurements of my 150W Phoenix when I get home as a comparison.

For taking the PAR measurement is it just set to Sun,sample and then take reading at different points and depth with the sensor head white spot pointing towards the light source to be measure?
Don't have to do any thing before taking reading?
There is no manual that tell us what to do?
evilc66 ready need your expertise

Maybe can publish your PAR measurement for MH and LED for us to reference.

Thank You evilc66

Sounds like you are doing it right, but the numbers are way off. For comparison, over my BC14, I have a 150W Sunpod, with a Phoenix 14K bulb (about 4 months old). Fixture is 4" from the water and at 6" below the waterline, directly under the bulb, I took a reading of 450-460 PAR.

Wow your reading so good. I must try again

I try to take reading again just now.
MH is 4 inch above water top .
At 6 inch below the water top I only get 300

evilc66 what do you think is the problem?

Hard to say. First thing I would check is the wattage draw of the ballast. A device like a Kill-a-Watt can be plugged inline to the ballast to measure what it is pulling. Electronic ballasts should be close to 250W +/- 10%, and magnetic ballasts will be over 250W. You mentioned it was a Hamilton bulb. How old is it? It shouldn't make that big of a difference, but we might as well make sure that it isn't the issue.

Hey evil what size drill and tap are you using for these cree XR-E LEDs? I've finally got a chance to run down to homedepot this weekend and want to get everything I need to finally finish my LED fixture.

I use M3 screws personally, but you can also use 4-40. You will usually find the drill and tap together, but tap drill charts are easy to find on the net.

so do coral not look as good unless you add uv so they have a uv output like MH?

That is yet to be seen The focus on the use of UV has mainly been for sps coloration and health. Lps and softies don't seem to be affected in the same way. I have had some sps do just fine color wise under LEDs without UV. Some people report less than satisfactory color under LEDs. My UV meter came in today, so I will be starting to gather data to see what we have to do, if we have to do it. The main problem is that we only have one source for UV LEDs so far, and the quality is questionable. It would be great if Cree, Lumileds or SSC did a UV.

hey i gotta question on how to wire my fans for my setup. im going to be using 4 of these: http://www.silenx.com/ixtremaprofans.asp?sku=ixp-11-14
and 2 of these for exhaust http://www.silenx.com/ixtremaprofans.asp?sku=ixp-34-16

what is the best way to wire these up? will i need a seperate power supply just for fans? i have heard that wiring them in series works for two fans, so should i have them wired in a series of three, with two in each one? that would make the fans wired in series, but the current would be the same through all , right?is this excessive cooling for an LED setup?

Go bigger. Larger fans pucsh more air for less noise. I know the SilenX fans are silent already, but a single 80mm or 120mm fan directly blowing down on the heatsink will provide better cooling than many small fans blowing end to end.

ok. still the same question on wiring. not that it is only three fans, should i still wire them all in series (24V/3), or should one be at 24 V and the other at 12 v(24/2 because they are in series)

i believe, and feel free to correct me, that if you wire 3 fans in series to a 24V power source,each fan would be running on 8V.

you add voltage when wired in series.

Is that correct evillc?

d.

when you wire something in series, you keep the current constant and the voltage is added. like your led setup. that's why the biggest voltage ever needed when using buckbucks is 24 (6leds x 3.7 + buckpuck= pretty darn close to 24v). when in parallel, the voltage stays the same throughout and the current gets added(the reason for current mirrors in strings of leds) there was a discusion on another thread about this same thing trying to wire 3 12 v fans together using a 24 v power supply. with this, best to use it in even numbers or just get a 12v walwart for like $5 and run everything in parallel and as many as you want as long as you dont surpass the current rating of the walwart, but that's pretty hard to do. most fans use .08a

is there a way to formulate approximately how many LEDS it would take to equal a certain MH wattage. for example, if i wanted to get at least the same par output or of a 250W, how would i formulate an array on how many LEDs to use. i know optics have some to do with it too and the depth of the tank.

thanks for the info on the wiring. can you show me a link of where to buy a 12v walwart with sufficient current?

from what i have read (i have yet to build my own setup) 40 degree optics will get you to 250 watt levels. the only other factor to consider is spacing, if you wish to eliminate spotlighting with a tight optic. i will be using 24 leds on my aquapod, with 60 degree optics if they fit under the splash lense. hope that helped