Discussion in 'DIY' started by rygh, Oct 4, 2010.
Thanks for that Spec . Ordered an extra fan if need.
While I was pondering one day and I came up with an idea on how to determine how much light a tank needs. Not perfect, but here is the thought:
When your lights are on, your corals are producing O2. There have been many studies that measure the oxygen concentration over time with corals that have shown that at some point, your corals reach a limit where more light no longer is used. There is a threshold.
Well, if you can dim your tank, you should be able to tune your lights using this experiment. If you started with your lights low and measured the O2 concentration in the water during the day, you should be able to record the highest level during the course of the day. The next day, you can turn the lights up a bit and you should get a higher level. If you kept doing this until the level stopped going up, my guess is you have reached the maximum amount of light your tank can use as your tank currently sits. Adding new livestock would change this.
To measure this, you could use a DO probe (preferred) but you could also measure PH as there is a pretty good indication of how the O2/CO2 relationship is changing in your reef using PH as a measurement. I have been meaning to post this formally as a discussion in its own thread.
Thoughts? Think it is worth a thread?
Hmm, a very interesting idea. Conceptually, it makes a lot of sense.
Problem one is getting the signal through the noise.
With a very accurate dissolved O2 or CO2 probe, it might work. Especially if you turn the skimmer off, and make sure
all top-off / additives are done in the middle of the night.
I really doubt PH would be accurate enough. I do have a probe, and it barely budges at all.
Problem two is that each coral is different, and at different depths.
So you could easily get a situation where the majority of corals are happy, generating
more O2, but you are bleaching others.
Second fixture has all the LEDs on it now. Finally.
Still have to connect them to the drivers.
Also, I am going to put some PVC rings around the LEDs, as pseudo-lenses.
If I was going to do it over, I would use 80-deg lenses I think.
This shows the main new fixture. WAY neater and cleaner than the first one.
[img width=144 height=129]https://lh4.googleusercontent.com/_eaxg2H-5-nk/TZlWH0y7xEI/AAAAAAAAASo/CUDQEgorfOI/s144/lights9.jpg[/img]
This shows the small cluster.
Cree XP-G CW + Cree XP-E RB + Luxeon Rebel RB
[img width=144 height=102]https://lh3.googleusercontent.com/_eaxg2H-5-nk/TZlWIZxsKRI/AAAAAAAAASs/rRV9DjCbPJs/s144/lights10.jpg[/img]
Looking pretty good Mark... Was definitely impressive in person.
I love how clean the wiring is.
Very nice. Love the small clusters. Like you when I finished my DYI I felt like going back to my old setup of T5 x MH. It was definitely lacking what I was looking for. I did a lot of research I felt. Ending with a RB,B,CW mix . I probably have spent more time trying to fine tune it ,then on the original build. Those clusters look like they might be my next project.
Thanks for posting all your finding and thoughts.
The wiring on the first one was so sloppy I really had to do it better.
And like so often, it is actually taking a bit less time overall, because I
am not spending a ton of time trying to track down which wire goes where,
and endlessly cleaning up the mess.
Lights are DONE!!!
Finally. It has been a really busy spring. Too many family things. (But a good priority)
For the second revision (left side), I changed the design a little bit.
I added small PVC "reflectors" around each LED.
I am VERY happy with the results. They reflect things back quite a bit, plus they tend to diffuse it a bit as well.
Nice and cheap compared to lenses.
They were simply epoxied to the heatsink.
With these, I feel that the side with the new lights is slightly but noticeable brighter.
Now the big question - to retrofit the old side??
New "Cluster" with PVC refelctors
[img width=144 height=117]https://lh3.googleusercontent.com/_eaxg2H-5-nk/TdHubkFz6mI/AAAAAAAAAUE/9ZXVMHuLy9Q/s144/led_trio.jpg[/img]
Under this is my RED LED. It has diamond diffusion lighting grate glued to the PVC pipe.
[img width=144 height=119]https://lh3.googleusercontent.com/_eaxg2H-5-nk/TdHucEtBaWI/AAAAAAAAAUI/641XSzc4OJo/s144/led_red1.jpg[/img]
All on. Hard to take a picture.
(Actually in this pic, one strand is out. Turns out I had a bad driver)
[img width=144 height=88]https://lh6.googleusercontent.com/_eaxg2H-5-nk/TdHucqQyUFI/AAAAAAAAAUM/SrAYICooTms/s144/led_all.jpg[/img]
[img width=144 height=102]https://lh6.googleusercontent.com/_eaxg2H-5-nk/TdHuaFOQglI/AAAAAAAAAT8/gCq0l0s7LOk/s144/leds_top.jpg[/img]
[img width=144 height=84]https://lh5.googleusercontent.com/_eaxg2H-5-nk/TdHuazkopHI/AAAAAAAAAUA/TrjY2bWfLlA/s144/led_r2.jpg[/img]
On the tank
[img width=144 height=84]https://lh5.googleusercontent.com/_eaxg2H-5-nk/TdHudmBRrqI/AAAAAAAAAUQ/GXB0f9zvBgQ/s144/leds_fv.jpg[/img]
Heat sinks are on the 1200mA drivers.
[img width=144 height=108]https://lh6.googleusercontent.com/_eaxg2H-5-nk/TdHuZaBvHTI/AAAAAAAAAT4/YagWN6LQgd8/s144/led_drvr_bx.jpg[/img]
Oh, almost forgot the most important.
Full picture of the tank with all the lights on.
[img width=144 height=37]https://lh6.googleusercontent.com/_eaxg2H-5-nk/TdHwbho2rmI/AAAAAAAAAUc/qEGr_Kd3qZ8/s144/full_tank_sml.jpg[/img]
interesting idea you had there with the "PVC reflector", what made you think that direction?
Also is there any cover over the LEDs? Last thing you want is any potential splashing on the exposed boards.
It's a PVC diffuser which by design, is a slash shield :-D
1) When I put the first (right hand) fixture on the tank, I had a TON of light coming out the sides.
It was quite annoying.
Sure, solvable with shades, but it fundamentally meant that a lot of light was coming out at a very wide
angle, then bouncing off splash shield and top of water.
So I really needed something to bounce the light back down more into the water.
2) I was getting more shimmer than I would like.
It has since toned down, as I get growth on the original bright white surfaces.
But it still meant I needed to diffuse the light a little bit.
So, the requirements were something that fits fairly neatly around the LED, diffuse reflection,
and is easy and cheap to make.
The other thought was to drill holes in acrylic, and paint it white, but PVC was a lot easier.
Yes, there is a 1/8" acrylic splash shield, covering the whole thing.
It was not attached on the other pictures. I will see if I can get a decent pic of it.
I also sprayed the entire thing with LED sealer.
Kind of yes.
It totally is for the reds. The diamond diffusion grating is glued to the end of the PVC, completely sealing in the LED.
And I could have done the same with clear acrylic glued to the pipes for the other LEDs, eliminating the need for a splash shield.
But the big splash shield actually extends over the entire tank, and serves 2 other purposes:
1) Keeps the jumpers in.
2) I have an intake to the vent system on one side, so I get controlled airflow across the top,
with negative pressure to the living room, so no humidity in the main house.
I turned the lights WAY down.
As I have mentioned in a couple of other places, my results for this LED fixture have been mixed.
Softies and some LPS are doing great.
But various SPS have shown a real lack of growth. Some tend to turn brown.
I don't really have that much coral yet, but enough to see that there is an issue.
In watching the Neptune 435G build, I notice they have a whole lot less LEDs than I do.
I had tried turning the lights up/down a bit before, with no real change.
But this time, about 2 weeks ago, I turned the LEDs down by a LOT. Roughly 30% lower.
(I did not do it all at once)
After only 2 weeks, results are encouraging, so I thought I would post this.
One of the little SPS frags that had turned a nice boring stage of brown is starting to color up again!
Too soon to know anything about growth though.
I still think I may supplement with a little bit of T5.
Specifically: One 36" T5 centered on each side. Using a UVL-10K Aqua-Sun.
That bulb has a fair bit of pink in it, so I might be able to turn off my red LEDs.
Wow, quite the combo!
No white at all, or are these supplementing MH?
I assume those are the Endor Stars.
Makes me want to think about rebuilding....
So many different wavelengths now. And cheaper.
In just a couple of years. A bit frustrating.
That is a lot of red. Looks nice, but hope it is not a bit of an algae issue.
Although I guess the 590 is more amber.
I notice Luxeon has 660nm deep red now as well.
I have a white string that is spread out more with a few blue; Going to run that 4 hours and these 10 hours; Noticed running the white 10 hours was giving me allot of algae no color (6500k cree); Will show some pics above a tank in a bit; this is actually for my frag tank ...
Also the reds only put out about half the light as blue leds; This light is producing around 1500 lums
They also are harder to solder and run on the warm side It would eventually overheat without the fan ...
[img width=800 height=600]https://lh3.googleusercontent.com/-4RF5kY3EPGM/Tyr0caODELI/AAAAAAAAA9c/GUjy8eZbFts/s800/IMGP7797.jpg[/img]
[img width=800 height=600]https://lh5.googleusercontent.com/-M_r799oLXkY/Tyr0encc8PI/AAAAAAAAA9k/gy5LEtx6FFw/s800/IMGP7799.jpg[/img]
[img width=800 height=600]https://lh4.googleusercontent.com/-JqUKTUwXw9s/Tyr0gVZc-7I/AAAAAAAAA9s/GCZCydUZ-zM/s800/IMGP7802.jpg[/img]
[img width=800 height=600]https://lh3.googleusercontent.com/-_ukRUE5cmd8/Tyr0h85JyAI/AAAAAAAAA90/SlyyqY6uEyw/s800/IMGP7804.jpg[/img]
Wow, seriously wild looking!
I like how the Cyan pops out as well. I am definitely missing that.
BTW: Lumens are not reliable ways to compare light at the ends of the spectrum. They are biased
by a human eye curve.
Looks very nice. Good job. I like the pinkish hue you get when you add the red. It's somehow relaxing to me.
I like how it make my tank with hair algae look better lol; Might just ditch the white leds in the future all together
[img width=600 height=800]https://lh6.googleusercontent.com/-SCZJiTqJF1I/TystRQfdfmI/AAAAAAAAA-A/7BP0fHkfQq8/s800/IMGP7805.jpg[/img]
Funny, with all that purple, pretty much any rock will look coralline covered.
I don't know about ditching the whites completely. Seems like it needs some orange, yellow, and other colors filled in.
But all personal preference.
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