DIY LEDs - The write-up

[TheFishMan65]

So are you saying add 8%?

 

[The Grim Reefer]

Mmmyep

 

[scrappy34]

I have a 30g tank that is 30x12x19

what led kit should I buy? I have no clue what I am doing so I need to be given a link please lol

 

[TheFishMan65]

What kind of coral do you want to keep? Go to my home page and find the summary link. 15-30 would be the recommendation, but depending on driver probably around 24.

 

[jkopp36]

In the middle of my build and have a question:

Seems like the parallel builds I've looked at have all had the negative leads running back to a jumpered junction block much like the positive side. Is there a reason I cannot just jumper the ends of the strings together and run one wire back? Prolly something obvious I'm missing.

 

[TheFishMan65]

I think the jumper blocks just make a neater connection. Also if you have to change something you only mess with one string. But you could put them all in a wire nut.

 

[Pierre3512]

Hi guys, I have been following your thread and a few others for quite some time and I must say you are making a great contribution to this hobby.

I have a 75g that has been running for 2 years with 4 T5 HO. It consist mainly of LPS and softies. I want to upgrade the lighting to be able to keep SPS and a few clams.

From what I read I plan to use 18 XML T5 CW and 36 XPE RB mounted on 3 U channels with the CW on the center channel.

Before I order all the parts I would appreciate your input on the following:

Is it worth spending the extra $ to get XML or should I stick to XPG?

Is the mix of 18 CW to 36 RB ok or do you recommend a different ratio?

Should I mix some NW and WW and if so how many?

Should I mix B with the RB and if so how many?

Is it ok to have all the CW in the center and the RB on both side or should
I mix them on the 3 U channels?

I plan to use 3 Mean Well 60 48P and run 2 strings of 9 leds in parallel from each. Is this ok or do you have a better way of doing it?

Eventually I plan to conrol this fixture with an Arduino based controller.

Your suggestions and recommendations will be greatly appreciated.

 

[TheFishMan65]

What prices are you looking at for LEDs and how long will you keep the fixture?

I have CW and RB only. I will probably be changing half the CW to NW. Have no opinion on blues.

From reading you don't have to mix them.

See if you can find the ELN-60-32(?) or something. OYu don't need 48 volts for 9 LEDs. If you go with less voltage you will have more current to split.

 

[Pierre3512]

Fishman tks for your answer from MW site I can find ELN-60-27 would that work or do you recommend another way of building the string i.e more led in each.

I intent to keep the fixture hopefully 4 or 5 years.

Are you recommending 50/50 CW NW

 

[Pierre3512]

XML CW t5 are $6.80 and XPG CW $4.94 is it worth the difference I saw very few build with the XML.

Your recommendation please

 

[reefermad619]

Not much of a difference between the XML and xpg unless driving them over 1.5amps. Xpg max out at 1.5amps while XML max out at 3amps. I would save the cash and run xpgs.

 

[TheFishMan65]

Pierre,
What is the max voltage on the ELN-60-27. With 27 volts and 9 LEDs you will only get 3 volts. I think you will probably need about 3.5 so go up one voltage step.

 

[TheFishMan65]

XM-L T5 are 260 at 700 ma and 2.9 volts or 128 lumens / watt
XP-G are 139 at 350 ma and 3 volts or 132 lumens / watt
WHAT! Somebody double check me.

If you have a deep tank the XML might help for penetration. XML produce almost twice the light (at twice the power) so price wise they are cheaper 1 XM-L versus 2 XP-G, but then you have to worry about spread because they will be further apart. IMHO I would probably go XP-Gs. The ratio there is 1:2 white to royal blue. If you went with XM-L the ration should probably be 1:4. I have not tried it yet, but am leaning toward recommending NW so now you would be at 1:1:8 CW:NW:RB. Just seems that spacing maybe awkward.

 

[patmack]

I have had my LEDs up for a few months now using a 50/50 CW:RB I have 24 xpgs and 24 XML being ran at 1.5 amps. the XMs are brighter but almost seem like too much with carclo optics. If I were to do it again I would leave out the XMs and do more RB or possibly some standard blues.

 

[kcress]

Thanks for that tidbit of info patmack. Do you really mean xpE? And you're really running the xpEs at 1.5A?

 

[jcgd]

XM-L T5 are 260 at 700 ma and 2.9 volts or 128 lumens / watt
XP-G are 139 at 350 ma and 3 volts or 132 lumens / watt
WHAT! Somebody double check me.

If you have a deep tank the XML might help for penetration. XML produce almost twice the light (at twice the power) so price wise they are cheaper 1 XM-L versus 2 XP-G, but then you have to worry about spread because they will be further apart. IMHO I would probably go XP-Gs. The ratio there is 1:2 white to royal blue. If you went with XM-L the ration should probably be 1:4. I have not tried it yet, but am leaning toward recommending NW so now you would be at 1:1:8 CW:NW:RB. Just seems that spacing maybe awkward.

That's right. But you are comparing apples to oranges. To compare the efficiency you need to compare them at the same current since lumens per watt decreases and the current increases. Check the numbers for XML at 350mA or xpg at 700mA in order to compare them fairly. The are fairly more efficient.

I haven't done par readings yet, but I ran xpg nw next to XML cw at 1000mA and the XML were noticeably brighter. I couldn't believe the difference.

I choose the XML be because I'm mounting pendants up high and I needed to get lots of light at the substrate through 3' of air and 2' of water. I'm using 40 degree oprice and running them at about 2000mA. Unless of course that is too much light. I think there is a good chance it might be.

I don't think I'll have heat issues because the heat sink is pretty sparse and there is no noticeable warmth at 1000mA. I also want some shadows but at that height I don't think there will be much spotlighting. I was able to save about 30% on LEDs due to needing less.

 

[zoakiller]

Sorry if this was adressed befor i didnt see it
Would it be cool to spray paint an led heat sink. I want it black and its for a nano only 6 leds
Thanks

 

[emora]

I contacted Apogee about which to quantum sensor to purchase for our application. (I hadn't realized I didn't need to spend $300 on a whole meter and could get this to use with my MM for alot less). I received such a good response I thought the information would be useful to post here.

"Hi xxxxx,

Yes, the SQ-120 (electric calibration) would be our best option for your application. These units are sealed and submersible up to 30m and are compatible with salt water. The SQ-100's are considered self-powered and will generate a mV output that you can measure with your voltmeter. We calibrate everything to a factor of 5.0 µmol/m2/s per mV, so just multiply your mV output by 5 to derive the photon flux value.

In regards to measuring LED's with the quantum sensor, there are some caveats to doing so. The following link shows the spectral response of our quantum sensor (http://www.apogeeinstruments.com/quantum/spectralresponse.html). As the graph shows, Apogee quantum sensors underweight blue light, and as a result, photon flux measurements for blue LEDs will be too low. They also overweight red light up to a wavelength of approximately 650 nm, above which they do not measure, and as a result, photon flux measurement for red LEDs will either be too high (if the LED output is all below 650 nm) or too low (if a non-negligible fraction of the LED output is above 650 nm). Additionally, LED's often have a very narrow spectral output, with a sharp peak of only a few nanometers. So, unless the quantum sensor has a perfectly flat spectral response, meaning it weights all wavelengths of light exactly the same, there will be errors. Electrically calibrated Apogee quantum sensors will likely provide a reasonable measurement for white LED's because they are broadband, and because electrically calibrated quantum sensors are calibrated under CWF lamps. However, for narrowband LEDs, like red and blue, Apogee quantum sensors will not provide an accurate measurement.

You can use the same spectral response graph (http://www.apogeeinstruments.com/quantum/spectralresponse.html) to get a relative idea of the error. For example, a 450nm blue LED will have a relative response of approximately 0.8. Therefore, you can figure that the photon flux reading from the sensor is probably reading approximately 20% low. Just remember, this approach is only relative so give yourself a wide margin of potential error. A blue/white configuration should give you reasonable accuracy, particularly from the broadband spectrum of the white.

Hopefully, that makes sense. Please let me know if there are any questions.

Regards,

Jacob Bingham
Applications Engineer
jacob.bingham@apogeeinstruments.com
www.apogeeinstruments.com
721 W 1800 N Logan, UT 84321
ph: 435.792.4700 fax: 435.787.8268"

What a great contribution (among many you've brought to this thread). Thank you.

 

[emora]

Sorry if this was adressed befor i didnt see it
Would it be cool to spray paint an led heat sink. I want it black and its for a nano only 6 leds
Thanks

I believe that spray painting will impede it's ability to transfer heat from the mass of the heat sink to the surrounding air. It would be beter to get an anodized heat sink

 

[kcress]

While that's true emora, all these heatsinks are such massive over-kill that painting them won't make any practical difference.