DIY LED fixture questions
 

So, I have finished my fixture and it is up and running (sorry, I'll post pictures soon). I have two questions:

question 1. My heat sink went up to ~105 F (40 C) in temperature. Is this an issue. I am running 56 LEDs on DIY heat sink from aluminum strips (with fins etc).

Question 2: Has anybody tested their fixtures with and without optics? If so, what was the difference.

My lights are ~5 inch from water and. I was wondering if the 60 deg optics would increase the intensity (less wasted light). I would like to know peoples experience here before shelling out another $60 for lenses!

But the lights are really cool!!
thanks

I'm not sure what the desired operating temperature is for the LED's, but you could always add another cooling fan if you are concerned. More cooling is never a bad thing! Can't wait to see the pics!

Take a temp reading from directly behind a LED. If it is under 158 degrees you are good to go.

you mean 158F not 158C ?

i would deff add some fans.....check the temp after a full day...just not a hour :)

ps...optics are gonna focus the light

what are the tank dimensions and spacing between the LEDs? Are they staggered, or do you have one color per strip?

My tank is 48LX18WX24H. It's a 90G tank. I have four rows of LEDs with alternate whites and royal blues on each row. Each row has 14 LEDs saperated by ~3 inchs (7 CWs and 7 RBs). Each of the driver runs 14 LEDs of same color.

I think that's a great idea. I'll set the thermometer. I have a one that can keep track of highest and lowest temps.

I spent the entire evening adjusting each of the drivers to deliver 950mA each (and I strongly suggest that everyone with Dimable drivers should do it). One of my driver was running at 1.3A. So no time to post pictures. but tomorrow I will have them for sure. All I can say is I like what I see. I almost want to add one more row of 14 RBs but I think I'll hold off on them as I want to see how tank does with this setup.

adding optics is a good idea, especially on taller tanks. As previously mentioned, they focus the light, making it more intense. What you end up with is a beam of light so to speak, rather than a ~140 degree spread from each LED. It does tighten the light spread a bit, so you may end up with some "shadows". Some people have experimented with using both 60 and 40 degree mixed optics to achieve more uniform coloration with fewer LEDs.

Hurry up with the pics!

Here are some quick pictures. I'll post some tank before and after in a couple of days.

A complete shot of the fixture:
LED side
http://i1177.photobucket.com/albums/...10427-1859.jpg

Backside:
http://i1177.photobucket.com/albums/...10427-1900.jpg

The fixture hangs inside canopy with the two 4' black shelf bars bought from HD. The ballasts and all the electrical connections are held by these bars too. The blue box in the middle is where are the junctions are and next to it is RJ45 connectors for VS port connection from apex (dimmers).

http://i1177.photobucket.com/albums/...10425-1447.jpg

http://i1177.photobucket.com/albums/...10425-1448.jpg

http://i1177.photobucket.com/albums/...10427-1900.jpg

This is how the fixture sits inside the canopy:

http://i1177.photobucket.com/albums/...10427-1904.jpg

http://i1177.photobucket.com/albums/...10427-1905.jpg

Some details of how the hanging bars are connected to the heat sink (via 3 inch spacers and details on fins on the heat sink.

http://i1177.photobucket.com/albums/...10427-1901.jpg

cont...

An acrylic splash guard was added on the LED side using nylon bolts and nuts and half inch spacers.

http://i1177.photobucket.com/albums/...10427-1901.jpg

Since the apex driver does not completely dim the light (at 15% or so the lights just go out :furious:, I had to add a separate set of moonlight that I ripped out of my DIY t5 fixture. I have been using LED mmonlights for the past 4 yrs (long before the Crees showed up :), bought from Besthongkong.com). This is the driver for moonlights.

http://i1177.photobucket.com/albums/...10427-1901.jpg

here is one of the moonlight:

http://i1177.photobucket.com/albums/...10427-1902.jpg

I have run it all day long and the temperature now does not seems to be an issue! if it does become too hot, this is where two fans are going to go:
http://i1177.photobucket.com/albums/...10427-1905.jpg
http://i1177.photobucket.com/albums/...10427-1905.jpg

I have adjusted all the drivers to 950 mA for now as I would like to run my LEDs close to 1 A.
The fixture seems to put out enough light. The CWs are a more brighter than RBs but I can adjust the CWs to 40% and get the colors I like! I will add an additional center strip of 14 RBs at a later stage and then I can run them brighter. For now the CWs are at 100% for 3 hr a day simulating high noon!

questions? comments? thoughts?

WOW! That is really nice. Very similar to what I have on paper but I am just now starting to gather equipment. Any chance we can get a full tank shot? I was planning 1:1 ratio of XP-G Cool White and XP-E Royal Blue but now you have me worried. I like a white look as I am running Iwasaki MH right now but I would like to be able to go a little more blue and see if I like it better. May have to rethink the 1:1 ratio.

Thanks SC Yeh! I found that CW are brighter than RBs. So you may have to have mix more of RBs if you you like 18K ro 20K look. AT high noon (100% CW and 100% RB) my tank looks like it has 10K MH bulb on it!

Also, I run my RBs from 11:00 A to 12:00 Midnight. From 11AM to 12noon it ramps to 100% and then stay at 100% until 11PM when it ramps back down to 0 in 1hr

The CW are run with following routine:
12:00 noon on
12:00 to 1:00 ramp from 0 to 40%
1:00 to 3:00 run at 40%
3:00 to 4:00 ramp to 100%
4:00 to 7:00 run at 100%
7:00 to 8:00 rampdown from 100 to 40%
8:00 to 10:00 run at 40%
10:00 to 11:00 rampdown 40% to 0%
11:00 Off

The tank really looks different at different times of the day. Each coral reacts to the light and expresses colors based on what time of the day it is :) really neat!

That's a very cool lighting sequence I will have to try something similar!

That's a great diy heatsink! I've been trying to figure out what to do with my new tank, looks like that's the inspiration :)

Where did you get the aluminum to make the heat sink? Very nice looking :beer:

Here are some pictures of my tank with LEDs on. Keep two things in mind when you watch these pictures :)
1. Mine is a very young tank, 2 months so most of the corals are tiny frags. but there is huge polyp extensions on these guys!

2. My camera is really crappy not to mention, the photographer (that would be me :)) is no good either. but the tank light is really crisp!

here we go:
http://i1177.photobucket.com/albums/...e/DSCN1072.jpg

here is the rightside of the tank.
http://i1177.photobucket.com/albums/...e/DSCN1073.jpg

The left side closeup
http://i1177.photobucket.com/albums/...e/DSCN1074.jpg

Side FTS

http://i1177.photobucket.com/albums/...e/DSCN1076.jpg

I recently got this feather starfish from LFS this guy is really cool and is happily spread out and eating!

http://i1177.photobucket.com/albums/...e/DSCN1079.jpg

Thanks for the honor organism. Glad to be inspire folks around me :)

Thanks you cubsare. I bought the aluminum from a local Hardware store. But it is also available from HD.

Very nice. Love the aquascape.

Still trying to decide on color combination. Some cameras auto adjust the color. How do the pictures on here compare to what you see in person? Is the color about the same, more blue or more white?

The pictures are actually slightly more blue than the actual tank. Also, for some reason, the pictures look more flat but in person the tank is much more crisp! I am looking at the tank right now and its 8:00 PM the CW are at 40% and the tank is looking like the way it looks in the picture here (CW were at ~75%).

Thanks for compliments for aquascaping. Took many tries on the dry land to get it to where it :)

Sweet! Thanks for the info. I think I'm going to stick with the 1:1 ratio. As stated earlier I like a whiter look with just a little blue and it looks like I would be able to get that at 1:1. Really nice setup. I hope mine turns out as nice as yours.

That light rig turned out great. I'm in the process of building my own. I'll be keeping 4 of my T5 bulbs (blues and purples) and go with a 1:1 ratio on the LEDs. Keep us posted on the progress.

:thumbsup:

Just picked up 32 feet of aluminum and a new 7.25 inch miter saw with a metal cutting blade. Let the fun begin.

Very nice! Congrats on your build.

Some thoughts: 1) If I remember correctly, the LEDs are fine, as far as temperature is concerned, if you are able to HOLD the heatsink. Double check this with Kcress.

2) If you add fans, think about how the air is going to move about inside your canopy. Because you made your bars running front-back, it would be hard to make air move within all the channels (help with convection).

Here is my build: http://reefcentral.com/forums/showthread.php?t=1973462

Thanks jpccusa.

After watching the temperature for a couple of days, I am not really concerned about it. The top of the hood is open and the heat sink is just warm to touch! I guess, I may not need the fan after all!! Save some $$ :celeb1:

Your fixture seems to be very nice as well. Actually I went through your thread before I started mine. You definitely are better than me on soldering LEDs. Lot's of useful information there :beer: