DIY LEDs - The write-up

[Sisterlimonpot]

I've been following this thread and you have sparked an interest in going LED.... I would also like to say that I think that what soundwave has done is great but the constructive criticism from lynxvs is only to take from soundwaves design and improve on it to make it more efficient, that is how we move forward in this hobby.
So what I’m saying is keep the ideas coming!!

[lynxvs]

Originally posted by EBOLII
lynxvs

perpendicular? Is that a pretty word for vertical? or do we just say "that-way".......and what do you mean by #2

so what does your mind recommend [#1] per 24"

What I mean by #2 is from what soundwave has posted the Buck Puck that he is using will not drive the LEDs at the rated current. I just suggested that the Buck Puck should be changed to the one that is adjustable.

From my experience 48 LEDs for a 48" tank would not provide enough light. I have to say I have not used the CREE I use Luxeon Rebels but they are almost identiticle.

In my tank which is 30" in length I have 60 LEDs.

Without optics I am reading just slightly higher PAR then what soundwave is reading....

[lynxvs]

Originally posted by goofyreefer
"1. Total LED count per 24" is not enough for high PAR.
2. LED driver will not provide the current required.
3. Fan airflow should be perpendicular to heatsink cooling fins.
4. LEDs are can not be removed easily from heatsink.
5. Light must be placed close to the surface of the water because of the lack of optics."

I don';t think any of these things are "problems" though. I hope soundwaves design works out well over the long run and look forward to hearing about it.

Just a quick reply with my opinion.

1.His PAR readings seem pretty high to me aleast higher than PC's and T5's I would imagine. Or do you not believe the reading soundwave is getting?

2. his driver seems to working just fine from the pics posted

3. Is it REALLY all that important which way the fan is mounted? Piont is to reduce the heat which he seems to be doing.

4. The LEDs can't be removed easily but if the LED's last 50,000 hours why worry about it really.

5. the lack of optics is Soundwaves preference which results in the lights being placed closer. Although they didn't seem all that close in the pics if I remember correctly but I could be wrong.

goofyreefer

1. I can't say I don't believe them because I wasn't there to see them taken....they don't seem unreasonable... it's just the fact that he is getting about the same PAR as me with half the LEDs and a larger tank that bothers me.

2. You can tell how the driver is working from the picture?

3. No you can run it without the fan with that big heatsink.... I was just suggesting mounting the fan so the air flows through the fins for maximum cooling.

4. That's what the data sheet says...... in the real world it's a little different. I bet soundwave has had a LED failure in the first couple of days of operation.

5. It also results in lower PAR. If you like the fixture on top of the tank this is fine but if you raise it up you need optics period.

[lynxvs]

Originally posted by Lutefisk
I'll confess that my post is a reaction to your description of Soundwave's project as being "flawed." Sure, it may not be what you would do but until you build a LED lighting system and post details about it that would allow most reefers to build their own I would only be guessing.

At this point I guess I would have to take the option you offer of disagreeing on a practical basis.

I think that it would be safe to say that about anyone, including Soundwave, can do a better job based upon lessons learned from this project.

Let's keep this "fun" and be helpful rather than judgmental.

1. Total LED count per 24" is not enough for high PAR.
Some people use 150 watt MH and others use 1,000 watt. It all depends on what you're trying to do and want to spend. "Not enough" is very subjective.

2. LED driver will not provide the current required.
See #1

3. Fan airflow should be perpendicular to heatsink cooling fins.
Yes, it could be more effective but it still gets the job done.

4. LEDs are can not be removed easily from heatsink.
See goofyreefer's point #4

5. Light must be placed close to the surface of the water because of the lack of optics.
Must? Should? Could? You pick. Early in engineering I did a lot on paper. Later I learned from a brilliant engineer that it's often better, when you can, to just try it out and see what works best. Soundwave can see what it looks like as he raises and lowers the fixture. Can you?

Now of course I'll have to confess to doing the same thing to your post that I'm complaining about you doing to Soundwave's design

Have fun

I guess some people are having a problem with the word "flawed" , OK , OK I will call them "engineering changes" .

I did post a build here several times a while back and if you click on my website you would see my build..... athough the information is outdated now I have had many engineering changes to it since.

I was hoping for lots of feedback on this but received little. Might be the reason I try to give more comments on soundwaves design.

[lynxvs]

Originally posted by EBOLII
goofyreefer your missing the context of the point. I don't feel lynxvs is being ill towards soundwave. He is just brash in his explanation. Most of the discussion is about improving the "soundwave version +"

Your right i'm used to talking with fellow engineers this is the way we talk to each other ... only worse.

[bebereef]

Originally posted by lynxvs
I guess some people are having a problem with the word "flawed" , OK , OK I will call them "engineering changes" .

I did post a build here several times a while back and if you click on my website you would see my build..... athough the information is outdated now I have had many engineering changes to it since.

I was hoping for lots of feedback on this but received little. Might be the reason I try to give more comments on soundwaves design.

I would like to know more about your bild before i go in to deep in my project.
i'm planning a 8 footer. ( 96 x 16 x 16.)

[lynxvs]

Originally posted by Sisterlimonpot
I've been following this thread and you have sparked an interest in going LED.... I would also like to say that I think that what soundwave has done is great but the constructive criticism from lynxvs is only to take from soundwaves design and improve on it to make it more efficient, that is how we move forward in this hobby.
So what I’m saying is keep the ideas coming!!

Finally someone who understands! Thank you.

[CJerome21]

I am interested in hearing more about the distance the LEDs are mounted from the water surface in relation to using or not using optics.
Soundwave what is the distance from your LEDs to the water surface and the same for Lynxvs?

I am planing builds for my two nanos and right now my PC light is about 2.25 inches off the surface.

[lynxvs]

Originally posted by bebereef
I would like to know more about your bild before i go in to deep in my project.
i'm planning a 8 footer. ( 96 x 16 x 16.)

Did you go to my web site? Wow that's a big tank...

www.photiczoneled.com

[ahoyhoy239]

lynxvs, look up "impingement jet" or "impinging jet", that is the basic configuration that soundwaves fans have with the heatsinks and it is a very effective method of heat transfer.

[lynxvs]

Originally posted by CJerome21
I am interested in hearing more about the distance the LEDs are mounted from the water surface in relation to using or not using optics.
Soundwave what is the distance from your LEDs to the water surface and the same for Lynxvs?

I am planing builds for my two nanos and right now my PC light is about 2.25 inches off the surface.

As you probably know optics will concentrate the output of the light source into a narrow beam so the light intensity is greater farther away but with a narrower beam. Of course this reduces the "spread" of the light to what soundwave calls the "spotlight effect"

There is something else going on when light strikes the surface of the water called "Snells Law" what this means is light will be refracted or bends when it hits the surface of the water so it works sort of like a lens but not as good.

This is only true when the light source is very close to the water. The ideal distance could be calculated I assume.

If you use optics you can raise the light and depending on the width of the beam have the same or greater light intensity with the same light spread. Remember even though you have a narrow beam the light will spread the higher you raise it.

I have tried hanging the light at 6" , 10" with optics and 2" without optics.

[lynxvs]

Originally posted by ahoyhoy239
lynxvs, look up "impingement jet" or "impinging jet", that is the basic configuration that soundwaves fans have with the heatsinks and it is a very effective method of heat transfer.

I did a brief search and don't quite see the connection but i'm not a mechanical engineer.... can you explain?

[Soundwave]

My fixture is 4 inches above the tank with another inch or so to the water. To lynxvs, the fans push air downward which allows air to flow through and out of the fins.

I've given it some thought an would like an opinion on this. I could add optics to the design but I would have to raise the fixture. So the thought is what if I cut a hole in the canopy for the LEDs and attached the entire fixture to the top of the canopy? I would think this would allow for more spread while using optics and allow the heatsinks to operate more efficiently as they would be pulling outside air instead of recirculating the air inside the canopy.

Any thoughts?

[ahoyhoy239]

heres a link i pulled off google, i didnt really read it but you can probably get the idea from the pics.

http://ieeexplore.ieee.org/ielx5/614...number=1362805

[CJerome21]

So would the consensus be that if the LEDs will be mounted close to the water surface, in the rage of 2 inches that optics should or do not need to be used?
Also with the Nanos they are frequently much shallower than larger tanks, for example one of mine is 8 inches another 15 inches so the depth the light needs to penetrate to reach the bottom is much less maybe not requiring the optic focused beam?

[lynxvs]

Originally posted by CJerome21
So would the consensus be that if the LEDs will be mounted close to the water surface, in the rage of 2 inches that optics should or do not need to be used?
Also with the Nanos they are frequently much shallower than larger tanks, for example one of mine is 8 inches another 15 inches so the depth the light needs to penetrate to reach the bottom is much less maybe not requiring the optic focused beam?

I would think with a Nano you should be fine without optics..

[EBOLII]

lynxvs or Soundwave so what does your mind recommend number of LEDS with optics per 24"

[lynxvs]

Originally posted by EBOLII
lynxvs or Soundwave so what does your mind recommend number of LEDS with optics per 24"

The magic number seems to be at least 24 LEDs per foot.. Just looking at the commercial products Solaris was using 30 per foot, Aquaillumination is using 24 per foot. I'm sure they had a bigger development budget then I have so I would shoot for that number.

[Doolin]

Don't the LED without optics give you the MH look anyway?

[Doahh]

LEDs are a point source with or without optics.

[Soundwave]

OK the decision has been made. I will be modifying the canopy and fixture this weekend. I will order the optics in a few minutes. The idea here is to cut a hole in the canopy roof about 9x36. I will build an enclosure for the LED fixture tomorrow and attach that to the top of the canopy. This will raise the fixture about 12" off the water surface which should still give me a decent spread with the optics along with making it brighter. Cooler room air will be drawn into the heatsinks instead of warm tank air. I'll post pics.

[jwhyne]

Cool, looking forward to the pics!

[ReefEnabler]

Here's a wiring question:

If an LED has a Vf of 3.6v, and you are using a BuckPuck with 24 VDC input, then this is just barely enough to power 6 of these LEDs in series; the Vf of 6 LEDs would be 21.6v (need 2v margin).

Could you wire two groups of 6 (in series) in parallel?? Basically after each group of 6 the wiring would connect back at the buckpuck essentially making two parallel groups of 6.

Anybody know if this will work? And if so, why don't we use more parallel wiring to power more LEDs with the Buckpucks?

Thanks

[Imzadi]

Originally posted by Soundwave
OK, let's see what I can answer...

Imzadi: For a 55g, Two rows of whites sounds like it would work just fine. However, if they are spaced too far apart, you will get two rows of white in your tank. If it were me, I would put the whites in the middle and the actinics on the sides.

That sounds logical! Actinics would be omni-direction...ish, where as the LEDs, as mentioned, would be point of source...

Thanx for the thought!

[ReefEnabler]

one more question thats probably been covered
Is it ok to mix LEDs of different Vf in the same series if they require the same current?

Ie a few cool white 3.85 Vf, 700mA LEDs mixed with some 3.15 Vf, 700mA LEDs.