High Tide Aquatics

Improved Color LED thread

A bit of a setback on the light fixtures. :(
Went to order the rest of the heat sinks I needed, and they were out.
I was basing a lot of the design on these surplus heats sinks, which for a while, the store had a ton of.

So, back to the drawing board a bit on the actual construction. (LED plan remains the same)

I will now be ordering four 5.9" x 40" big heat sinks, and gluing them to that.
No real difference overall, other than it increases the cost.
Might even make the build a bit simpler.

Here is the LED/heatsink layout. Left side will be a mirror image.



Attached files /attachments/sites/default/files/mainlightsdwg.jpg
 
I guess my drawing notes were a little off.

The cool blue circles are the CLUSTER, not the single LED.
= cool white + 2 x royal blue.

The neutral white is the cluster as well.
= neutral white + royal blue + blue + red
(Although still flip-flopping on making that blue a Cyan.)

I still plan to group the white/blue/color tightly, to reduce color banding.
Even though now with a few large heat sinks, I can do whatever I want.
 
Backup plans:
I have received a fair amount of people wondering if I should risk an all-led design on a big tank.
So I thought I would clarify my backup plans:

1) If the colors are bad, or it still looks washed out to me:
Basically, a failure on the "human eye" side.
In this case, the plan was to add 3 x 36" standard T12 bulbs on each fixture.
So six total, at 30W each, for 180W extra.
Not much power, but this is really to cover missing spectrum, not for major light source.
Most likely the UVL actinic white with internal reflector.
I can drop the LED power down a bit as well.

2) If the corals die and it proves impossible to get PAR in range.
Basically, a failure on the "coral biology" side.
In this case, I will move the heat sinks outward on the fixture, and only turn on the royal blues.
I will then add 2 x 175W-250W metal halide lamps per fixture between the heat sinks.
Those would be fairly daylight-white, and I would use the blue LEDs for actinics.
But I think this failure is fairly unlikely.
It may take time to get PAR correct, but it should be over sized, so easy to turn power down.
 
Starting up on the lights again this week.

Heatsinks and brackets are done.
Four 6" x 39" heat sinks.
Shown is the right hand fixture.
A bit tricky to attach heat sinks to cross-L brackets since there was not really room for a nut between
the fins. Ended up tapping the heatsink. Worked well, just extra work.
Now to attache some acrylic below it, to protect LEDs, and then glue on a ton of LEDs.
Heatsinks are sanded and ready for epoxy.





From Aquarium_Release
 
# THE PROBLEM WITH COOL WHITE + ROYAL BLUE:
This is the most common setup these days.
And like mentioned above, the results are actually "Pretty Good".
Plus you can pretty easily tweak the amount of blue to get the color temp you want.
The thing is : It looks nice given a fairly uniform white target.
So on bare live rock, can look great.
The problem is : It is your eye fooling you. The spectrum is actually pretty bad.
You have HUGE peak of blue at 450 nm.
You have a bump of light from roughly 525 nm to 625 nm, green through orange.
But you have almost zero reds, especially deep red.
Plus, you miss Cyan, and the deeper violets.
So while you can trick the eye into thinking it is white, it is actually far from it spectrally.
The problem is if you have a red coral for example, and no red light, it will look almost black.
Now there is red, just not that much, plus there is fluorescence, so you will see some reds.
But in general, it will look washed out and greenish-blue.
Also, chlorophyll need that missing red.
Click to expand...
This "problem" is only a problem with DIY LEDs, off the shelve LEDs won't have this problem. There are quite a few fixtures that utilize cool white and royal blue LEDs with great results...

# THE PROBLEM WITH EVEN SPACING:
Again, this is the most common setup these days.
A lot of systems, even professional, evenly space the LEDs, often alternating White / Blue.
That is wrong. You really want to keep LEDs of different colors very tightly clustered.
If you don't, you can get terrible color banding effects, especially in shadows or with a rough water surface.
What happens is that you will have some regions where blue dominates, and some where white dominates.
For example, directly under a blue, next to a high rock that blocks the nearby white.
By itself, normally the color is really not that different, since light bounces around a lot.
But your eye is really good at detecting subtle differences in a pattern.
As a result, you get a mottled effect, and really notice the odd bluish areas or odd yellowish areas.
Note that optics make clustering hard, and make the problem worse.
Click to expand...
This problem is easily prevented by using the degree right lenses, that idea that optics would make it worse is crap...

I'm not sure where you get this info from but I'd second guess your sources. Unfortunately there is a lot of crap out there.

Notes:
No lenses. There will be a 1/8 acrylic sheet between LEDs and water, as part of light fixture.
Click to expand...
May I ask why? although I properly already guessed the answer
 
I've learned a lot from reading this thread. Very informative on LEDs. :)

I am not an expert on lighting but here is my personal beliefs...
When laptops first came out the cheapest were in the thousands, but now you can find an even better one for a few hundred. I believe the same thing will happen with LEDs. I'm not a big LED fan as of now because to me it's just another light that makes your corals look pretty but doesn't give them 100% perfect growing conditions. On the other hand I've heard MH grows corals much faster (and possibly healthier because it has a better lighting spectrum?? Idk...), plus IMHO I think that MH brings out the natural colors of the coral that the sun would bring out on the reef which is what I personally prefer. I would try LEDs, but the price tag is currently too high and I've heard too many downers about them. As I stated above, I strongly believe that the price will lower and the quality will increase, so I'm going to wait on going LED for a couple of years.

Another reason I'm discouraged from going LED is because I bought a zoanthid at an LFS and it was under a really expensive-looking royal blue LED. I brought the zoa home and put it in my RSM that has 110w PC. It wasn't too colorful to start with, but then it colored up. I visited the LFS again recently and took a look at another frag of the zoa I had gotten under the same LEDs I had gotten mine from and it looked pretty much the same under my PCs. The only difference was that under the LEDs the blue on it was emphasized by the LEDs having more of a blue spectrum. I'm not saying this is true for every coral, but it's true for at least that one zoa that I really enjoy. :)

Those are just my personal thoughts, and as I said I'm not an expert on LEDs. :)
 
Joost_ said:
This "problem" is only a problem with DIY LEDs, off the shelve LEDs won't have this problem. There are quite a few fixtures that utilize cool white and royal blue LEDs with great results...
Click to expand...

Disagree. Off the shelf LEDs have the same issue.
And yes, specifically those with cool white + royal blue only.

1) Importantly, color is really a matter of personal preference.
Some people are very happy with standard LED systems. I envy them.
Unfortunately, the color issue I describe really bugs me.
Perhaps because my day job is video/imaging electronics, and I am super picky.
Just like some like 20K, and some like daylight, everyone is different.
Plus, it is expectations. For a while, I was quite happy with a cheap coralife PC light.
But after seeing some really nice MH+Actinic setups....so much for that.

2) Other than the DIY setup that is simply built wrong, how would store bought ones be better???
Everyone has access to the same LED technology. And the color problem has to do with
the spectrum on LEDs, not the way you connect them to the fixture.
So what magic could a big manufacturer do.
In fact, because of penny pinching, they often use inferior LEDs, and make the problem worse.




Joost_ said:
This problem [banding effects] is easily prevented by using the degree right lenses, that idea that optics would make it worse is crap...
I'm not sure where you get this info from but I'd second guess your sources. Unfortunately there is a lot of crap out there.
Click to expand...
Not crap. It is basic physics.
The tighter the beam, the less overlap between LEDs and the more defined the beam, so the worse the color banding.
The widest beam is no-optics, so any optics make it worse.
Draw out two sets beams on a piece of paper, one set wide, one set narrow, and it might be more clear.


Joost_ said:
Notes:
No lenses. There will be a 1/8 acrylic sheet between LEDs and water, as part of light fixture.
Click to expand...
May I ask why? although I properly already guessed the answer
Click to expand...
The LEDs are close to the water (about 2"), so the acrylic sheet is there to keep moisture away
from all the electronics. It unfortunately will reduce the light slightly.
Note that I have a vent + fan set up, to draw fresh air across the water in a controlled way.
 
Euphyllia said:
I strongly believe that the price will lower and the quality will increase, so I'm going to wait on going LED for a couple of years.
Click to expand...

I think that is a VERY good idea.
It really seems to me that as far as what is available to buy off the shelf right now, MH is the way to go.
Perhaps MH + LED supplements to replace actinics.

I do believe that manufacturers COULD produce a higher quality system if they wanted to.
But it takes a lot of extra LEDs to fill in the spectrum, so it would be very expensive
compared with other competing systems, and would not sell.
Frustrating for me, and probably manufacturers as well.

I HOPE I can actually get it right myself, by spending a bit more on LEDs.
With no markup to worry about, it is not as expensive.
 
Euphyllia said:
Another reason I'm discouraged from going LED is because I bought a zoanthid at an LFS and it was under a really expensive-looking royal blue LED. I brought the zoa home and put it in my RSM that has 110w PC. It wasn't too colorful to start with, but then it colored up. I visited the LFS again recently and took a look at another frag of the zoa I had gotten under the same LEDs I had gotten mine from and it looked pretty much the same under my PCs. The only difference was that under the LEDs the blue on it was emphasized by the LEDs having more of a blue spectrum. I'm not saying this is true for every coral, but it's true for at least that one zoa that I really enjoy. :)
Click to expand...
Could be the lighting, sure. But there are SO many other factors that affect coloring up,
it is really hard to read too much into that.
 
Qwiv said:
You looking to source any LEDs soon?
Looking to add some to my kits. NW, Blue, Violet.
Click to expand...
Well, if I have some leftovers at the end, sure.
But I buy from ledsupply + cutter + digi-key, so strictly a personal project.
 
I know, didn't know if you were done buying and experimenting. I still have a bunch of LEDs from old builds, figured I would use them over a frag tank I am working on but an short some colors and looking to try a few others. I can order myself when the time comes.
 
Quick update - finally got word that my LEDs will be shipping this week.
About time!
Turns out it was a problem with the standard blue ones, which I could have bought anywhere.
Oh well.
Time to get in gear in wiring up the drivers and such to be ready for them.
 
Update:
The LEDs finally showed up last night!!
So no more excuses for that single coralife aqualight that is over the tank now.

Of course, they showed up un-labeled.
Well, I needed to test them anyway....
Actually, I can tell the difference just looking at them, but not super obvious,
so I am a bit worried about making a mistake.

Now for a whole lot of soldering. :tired:
 
yardartist said:
Dave found that a small scratch on the LED pads helped the solder seal to it better.
Click to expand...
Interesting, I will try that.
I do solder leads on the LEDs before gluing them to the heat sink, which makes it easier as well.
Soldering afterward can be almost impossible for some vendors.
 
One of the two driver boards is done.
8 x 700 mA drivers
3 x 1200 mA drivers
1 x 300 mA drivers
1 fan relay
And tons of wires for power, PWM, lights, fans, and so on.
Plus a few bypass caps, just for fun.

And of course, my heat gun died, so excuse the temporary wire-wrap nuts and electrical tape.
(Wires are soldered inside, and will use shrink tubing one new heat gun arrives)





From Aquarium_Release
 
Getting some of the LEDs on the fixtures.
Here are the 18 XP-G LEDs on one, glued on, with leads soldered, but not connected together.
I still have the 36 RB, plus some misc. to do.





From Aquarium_Release
 
rygh said:
yardartist said:
Dave found that a small scratch on the LED pads helped the solder seal to it better.
Click to expand...
Interesting, I will try that.
I do solder leads on the LEDs before gluing them to the heat sink, which makes it easier as well.
Soldering afterward can be almost impossible for some vendors.
Click to expand...

I tried the scratches. Did not seem to make a difference for me. Oh well.
But I never really had that kind of solder flow/stick problem.
Lack of rosin?

What really amazes me is how different they are to solder between vendors.
Most of the cutter ones are easy. The ledsupply ones are much harder.
I think it all has to do with the thermal path between the pads and package slug.
Quite possible that harder = better star package.
 
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