(Another) DIY LED Build - Linear Design

[big cats]

guess I shoulda said tighter optics would work best for MY smaller tank..When you are only working with a foot and a half of coverage space in either direction it makes sense to use tighter optics. Right? This way you maximize the light that gets cast on your corals and rocks rather than the space between them and the wall that is empty...It really just depends on your tank, and yes, distance above the water does play a part in it as well.

Mike from RapidLed called me back today and said I should go with 20 LED's at 12" off the water and 80 degree optics. I was thinking of going 9" above and using the 60 degree optics? Or maybe even how you plan to set yours up with the 80 degree optics in the middle and the 60's in the front and back.

Not sure yet what I'm gonna do. How hard is it to take the lenses off and put them on and such? are each size lens compatible with all the LED's or do they only work for the ones you order them with?

[TheFishMan65]

Another possible issue (no one has reported on it that I have read) with tight lenses is the light is more focused so the corals may grow differently since there is no light coming from ths side.

XP lenses ork on either the XP-G or the XP-E - I have checked wih Mike in the past. I think they state different angles, but I think that is caused by the refraction/reflection of the different wavelengths rather than th actual lens.

[big cats]

If I set up the lights this way, (bare with me on the diagram, I don't have any fancy diagram programs)

-xxxxxxx-
-xxxxxx-
-xxxxxxx-

with the x's being the LED's, and gave the outside lights a 40 degree lens and the middle row a 60 degree lens, that should spread the light fairly evenly around my tank right?

[Meshmez]

Originally Posted by big cats

Mike from RapidLed called me back today and said I should go with 20 LED's at 12" off the water and 80 degree optics. I was thinking of going 9" above and using the 60 degree optics? Or maybe even how you plan to set yours up with the 80 degree optics in the middle and the 60's in the front and back.

Again, youre thinking backwards. The closer you get, the wider the optics you should run.

IMO I wouldnt run anything tighter than 60 deg at 9" off the water. Since you are packing them into a small area though, you MIGHT be OK with tighter lenses. What happens when you get tighter lenses as you get closer to the water is you end up with spotlights. The tight angle doesnt have enough room to spread out before it is in the water. Also, as fishman stated, you end up hitting the corals only from the top, and not the sides. This is probably fine with softys and LPS, but SPS will end up with shadows that may be bad for the coral. Another thing is you dont have a deep tank, so with tight optics at a closer range it is easier to burn corals, ESPECIALLY if you dont go with a dimming system.

you normally mount the lenses with a small dab of epoxy which is easy to break off if you want to change optics.

[big cats]

So then I should run at least the 65 degree lenses and the 80 degree lenses. I just don't want the light to be too spread out (if that even makes any sense). I highly doubt it will look the way I think it will but for some reason all I can think of when I hear 80 degree lens is like taking a flashlight, shining it against the wall, and then walking back until the light gets dimmer and dimmer..I know with LED's that would take a great distance, but I just can't seem to get the thought outta my head..

If I ran them all on 80 degree lenses, how would the overlapping of colors affect the color of the lights? I plan to have at least a 2:1 of RB to CW, but if they all overlap is that going to defeat the purpose of having my ratio?

[Meshmez]

The overlap will not change your ratio, assuming you have a even pattern across the array. Your ratio is determined by the number of each LED that you have, really you WANT them to mix well. If they dont you end up with color separation and you can get some really funky multi-colored shadows in your tank. Obviously if you put all your blues on one side and all your whites on the other it wont be even and you will basically have a different ratio across the tank.

You are right about your flashlight on the wall moving back getting dimmer and dimmer. It is EXACTLY what is happening here, but the fact of the matter is at the distances we are talking about you are still getting plenty of light in the tank. ALSO, think about your flashlight analogy with a light you can focus, such as a mag light. when you are a foot away from the wall it doesnt really matter where you have the focus adjusted, you get pretty much the same brightness. As you move back to 5 feet from the wall you will have to focus it tighter to get the same brightness as before. Move back to 10 feet and you have to make it even tighter. same goes for the LED's, except we are using multiple light sources (individual led's) which is where the spotlighting comes into play with a tight lense at a short distance from the water. If you put all 20 of your leds, really close together you wont get spotlighting of individual LED's with say a tight 45deg lense, but you also wont cover your whole tank, and you will probably toast anything under those lights. You spread them apart more and use a wider lense to get more coverage. YES the light is less intense for the same number of LEDs but you will NOT be able to run them at full power with 45 deg lenses anyway. (and FWIW you probably wont be running them at full power with 60 or 80 deg lenses either)

I hope that all made sense. You are right in your thought that you will harness more of your light into the tank with a tighter lense, and I know that is why you keep wanting to go with a tigher lense. But in reality, you will be getting PLENTY of light into the tank with 60 or 80 deg lenses at under 12" from the water, and it will be more tunable to make your corals happy and not just burn them. Some people even run NO lenses on their systems at <10" from the water.

[big cats]

Well what would the advantages and disadvantages of having no lenses on the LED's be? obviously not being able to "control" the light placement would be a disadvantage, but what's an advantage?

[Meshmez]

Originally Posted by big cats

Well what would the advantages and disadvantages of having no lenses on the LED's be? obviously not being able to "control" the light placement would be a disadvantage, but what's an advantage?

you arent really going to "control" or "aim" the light with the lenses. I guess you could, but you would have to tilt the whole led, not just the lense.

For me, having NO lenses (which is effectivly a 120+ degree lense i think) at ~10 inches from the water gave me a really weird shimmer. Also in the case of no lenses you do end up lighting the wall and everything else in the room because the light will completely miss the tank, and without a canopy light goes EVERYWHERE. and it is BRIGHT. putting a lense on (even an 80) makes it so the light goes down into the tank. It is dimmer with no lense compared to the 60, and i think that is what led to my weird shimmer. I think I was getting too many shadows, so the colors were getting weird. If you were planning on mounting it an inch or 2 off the water (as some people do) I think it would be fine. But at 9" (which i think is what you said you planned to do) I would definately use some kind of lense, I just think you will be happier with a 60 or 80 or a mix as opposed to 45's. In all honesty, optics are pretty cheap, and you can change them out if you dont use a ton of epoxy to install them, so you can give different options a try. Especially at only 20 leds, you arent really going to break the bank if you want to try something different.

[S2minute]

That's interesting Mesh. The max i can go with the height of my fixture will be 9-10". I have 70 40 degree lenses and 70 60 degree. I WAS going to use the 40s on the outside edges only but after reading this maybe i'll use the 60's on the outside and buy 80s for the rest,(i have 144 in this array).

[big cats]

Now here is my other question. What is the minimum of the CW LED's I can run on a driver? Because I want to have a 2:1 ratio of RB to CW, and that is looking pretty hard to do with only 20 LED's. Would I be better off just getting 24 and running at a lower power level? So many things to consider and I'm running out of time! Haha. Tank is half way done cycling and I still don't have lights :O

[Meshmez]

Originally Posted by S2minute

That's interesting Mesh. The max i can go with the height of my fixture will be 9-10". I have 70 40 degree lenses and 70 60 degree. I WAS going to use the 40s on the outside edges only but after reading this maybe i'll use the 60's on the outside and buy 80s for the rest,(i have 144 in this array).

if you already have the lenses, give it a shot. I was able to get the lenses to stay on the leds temporarily (VERY TEMPORARILY) without gluing, this allowed me to mess with different configs. Im assuming with an array that big you have a 6-8' tank? you should be able to set up a couple different configs next to each other at the same time to see the different light patterns side by side. for instance, on my 4' tank I used either side of the support as a break for different lense choices so I could stand back and look at the differences side by side. That way also you could just buy enough 80's to do one section for testing instead of buying them all up front.

[Meshmez]

Originally Posted by big cats

Now here is my other question. What is the minimum of the CW LED's I can run on a driver? Because I want to have a 2:1 ratio of RB to CW, and that is looking pretty hard to do with only 20 LED's. Would I be better off just getting 24 and running at a lower power level? So many things to consider and I'm running out of time! Haha. Tank is half way done cycling and I still don't have lights :O

Depends on the driver. Rapid LED carries a Meanwell ELN-60-27D dimmable driver that is good for 5-8 LED's, the ELN-60-48D is 8-14 I think.

[big cats]

Okay so I have a couple ideas on how to set my LED's up, figured I would post em here to see what people think and if/how they would change it.

(Not the best diagram but it gets the point across)
CW- Cool White
RB- Royal Blue

First is my 20 LED configuration
4 rows of 5 LED's per row.
The horizontal rows that start with CW will have either 60 or 65 deg lenses
The horizontal rows that start with RB will have 80 deg lenses.


- CW RB RB RB CW -
- RB RB CW RB RB -
- RB RB CW RB RB -
- CW RB RB RB CW-

Configuration 2:
(Specs are the same just different number of LED's)

this configuration is 3 rows of 8 LED's for a total of 24.


- CW RB RB RB RB RB RB CW -
- RB CW RB CW CW RB CW RB -
- CW RB RB RB RB RB RB CW -

Let me know what you think.

[TheFishMan65]

I think 4x6 might be better.

[Meshmez]

Not to throw another decision into the mix (I know its tough, I went through about 50 different "final plans" before I bought my lights, and then I still changed once I got them running...) but have you considered neutral whites in place of some of the CW's? using all CW tends to give the tank a very washed out look. My current setup is 20 RB, 4 NW, 12 CW. I think Im going to be changing to 22 RB, 6 NW, 8 CW.

[big cats]

Well, what is the difference between the NW and the CW?
How many would I switch out and where would I put them?

[Jimsreef]

What is the NW led 4500k or 6500k?

[Meshmez]

Originally Posted by big cats

Well, what is the difference between the NW and the CW?
How many would I switch out and where would I put them?

That's a good question...

Neutral White is 3,700-5,000K color temperature
Cool White is 5000-8,300K color temperature

Meaning the Neutral White is a bit yellower, allowing the array to cover more of the spectrum. Some people are going to all NW instead of CW... It really comes down to your preference of the color you want in your tank. Unfortunately, looking at pictures and videos can give you a little bit of an idea of what it will look like... but until you see it in person in your tank you really wont know...

As far as your placement questions, does your tank have a center brace?

[big cats]

Well, in my 4x5 configuration, I was thinking maybe switch the middle two CW to NW? That would blend the colors all fairly well right?

[Meshmez]

Originally Posted by big cats

Well, in my 4x5 configuration, I was thinking maybe switch the middle two CW to NW? That would blend the colors all fairly well right?

Thats probably what I would try, ya.

[TheFishMan65]

I would go at least 50% NW, but color is personal preference.

[SWF]

Hi Cesar,

Thank you so much for all the information you have on this thread. I am also
planning to build a LED fixture based on your design. I started a new thread on it. some how i did not get a reply on that... guess no one noticed it !!!

http://reefcentral.com/forums/showthread.php?t=2122790

Since i was anyway inclined on following your design i thought i will ask my questions on the build to you here on this therad .. hope you dont mind.

1) How many LED's would i need. My tank size is 44(L)x 24(W)x24(H). I am planning to
have a mixed reef .. SPS and LPS. I was planning to get 2 set of diy kit with 36 led's dimmable drivers from rapid led. Also, i would like the fixture to be at a height of atleast 12 inches or more from the water surface. is 72 Led's enough or is it a bit too much ?

2) Other than the items listed in the rapidled link above. what else i need
to purchase. I see a lot of people usings resistors/ pots and lot of other stuff.
Can you list out all the additional things that i will need. Acessories that would be help make the build easier like connectors or other stuffs that you've used.

3) In the future I would like to have my LED lights on a controller .. or maybe build one based on the Arduino controller. What do i need to make sure while i build so that it is controller compatible in the future.

Hope to get your inputs on my above questions..

Thanks again,
Best Regards,
Ravi

[TheFishMan65]

1) IMHO 48 might be enough, but 72 is good with dimmable drivers
2) Rapid has prety much everything unless you are wiring in parallel.
3) What driver are you using? Assume the ELN you will want the P version for an Arduino, but this make dimming early on much harder.

[SWF]

Hi FishMan65,

1) is 48 really good enough for a tank with a foot print of 44x26x24 .. I am planning
to have a mixed reef and hopefully move on to a SPS dominated later on.
I think with 48's i could make 4 strings. Will these give me an output close to say
a 250W MH.

2) I am planning to get ELN version P.. I was thinking of getting a DDC-01 PWM
Controller since am not really that good with electronics. maybe later on try a Arduino

Thank you so much for your response.

Best Regards,
Ravi

[katchupoy]

swf,

I'm with fishman...

1) based on my computation, 48 is good. But maybe 60 will work better because of the 24 inch height? This is no issue if you are doing it linear? Since you can always add a set of 12 later on.

2) P is designed for pwm. But I have D connected to my arduino for 13 months now and see no issue. I cannot guarantee that it will las forever but fishman s correct that P really suck at the early part of dimming. They just jump in around 15-20% brightness. Unlike D that starts at around 5-10%.