DIY LEDs - The write-up

[TheFishMan65]

From what I have read X PAR in LED is not the same as X PAR MH. I think this is because LED have a lot more blue (Remember all whites have a lot of blue). If you look at the PAR sensor datasheet it only measure 60-70% of the PAR at the blue end. LEDs have less red and green than MH (I can't remember the MH spectrum). So in one sense you could say that X PAR in LEDs is 1.4X PAR in MH. I am not sure if this is true, but I am leaning this way. Discussion welcome

 

[TheFishMan65]

XP-E tend to have a wider spread so they cover a wider range. They are also later so although the efficiency bins over lap it is easier to find efficient XP-E.

 

[brassmonkyballs]

From what I have read X PAR in LED is not the same as X PAR MH. I think this is because LED have a lot more blue (Remember all whites have a lot of blue). If you look at the PAR sensor datasheet it only measure 60-70% of the PAR at the blue end. LEDs have less red and green than MH (I can't remember the MH spectrum). So in one sense you could say that X PAR in LEDs is 1.4X PAR in MH. I am not sure if this is true, but I am leaning this way. Discussion welcome

I've read the same thing...and its well known that there's a considerable PAR spike in the RB wavelength. Regardless same question...if X to X why would you dim to lowest level and acclimate for a year? If its 1.3-1.4X the question remains.

Reality is most of us don't own a meter so my question is not easily answered. My guess is that people who have had problems are using way more LEDs than they need...you look at these tiny lights and think no way....and then because it looks so good blasting away you leave it.....I suspect the 2X PAR+ (or whatever) comes into play. I know of a number of people who put way too many on their tank and now don't even light them all...

Good discussion

 

[brassmonkyballs]

I don't see a difference other than smaller package and possibly less optics options. A great thing I like is that the lenses are smaller so it makes possible to do lower profile lamps. If you don't use any optics the viewing angle is wider than XR-E but in most cases you'll want to use optics.

My understanding is that the XPE RB output 500mW of Radiant flux and the XREs 425...both at 350ma. I also thought the XPEs were rated for 1000ma but I can't find that anywhere in the spec sheets now. At any rate...the XPE puts out more and is a smaller package. I have both and the XPEs are nicer in my opinion...smaller, cleaner package. The XREs have the larger bubble lens over the diode, the XPE is dinky if its a bubble lens.

 

[SC Reefaholic]

Want to mount my (2) ELN-60-48Ds in my cabinet and run the wires (2 parallel strings of 12 XP-E RB LEDs and 2 Parallel strings of 12 XP-G CW LEDs) about 7 feet to my DIY LED fixture.

Can I do it and what effect will it have on the LEDs performance?

What guage wire should I use from the fuse/resistor blocks to the first LED?

Anyone?

 

[kcress]

Holic. That should be fine. No performance issues.

You should wire all your LEDs together with 22 or 24AWG. I'd probably use 20, or at most 18AWG, to cover those 7 feet.

 

[Jimmy54]

I also thought the XPEs were rated for 1000ma but I can't find that anywhere in the spec sheets now.

Here's a link where you can find all about Cree LEDs.
It doesn't really apply to our way of color mixing, but some verry interesting articles, like Led Color Mixiing in the section "Application Notes" is really worth reading.

 

[SC Reefaholic]

Thanks Kcress.

 

[tonythefish]

Here is my set up
3 22x26 heat sinks with 40 Cree 3w XP-E's 2/1 ratio blue/white with 4 XP-G for high noon each. Total 120 leds

 

[pjcforpres2020]

Here is my set up
3 22x26 heat sinks with 40 Cree 3w XP-E's 2/1 ratio blue/white with 4 XP-G for high noon each. Total 120 leds

That is very pretty, I like blue! Does that blue/white ratio feel a little too blue though? Or is it a great combo for the livestock you? Could you maybe post a picture of the tank lit up?

 

[tonythefish]

In that pic only the high noon whites are on . I use 12 high noon for ~ 45min to transition to the whites , So in the end I run a 2/1 ratio blue/white . I have the blues at 9v and the whites at 8v ( 750mh ) . I still need to figure out how to take a good picture of the tank . I only have a digital camera that cant handle it .

 

[Closser]

Wow...what a thread! I haven't posted here before but I've sure spent all sorts of hours reading and with your help (thanks especially to Fishman's summaries!) went from DIY virgin to proudly enjoying LEDs on my nano.

Quick question: I'll be getting a small sump/fuge soon and I'd like to make a 12'' fixture to grow the macro algae. I'm thinking 6 CREE warm whites, but I'm wondering how best to drive them. Is the ELN-D that I used in my first build going to be overkill? I suppose I've got upgrade potential

Also, any experience with the red Osram 660nm I just saw on RapidLED? Maybe I could mix red/white for algae? Thanks!

 

[patmack]

You should be able to use an ELN. You will likely have to adjust the voltage down to about 24 volts. I think that is the lower limit of the ELNs.
BTW I use cool whites on my fuge and seem to get pretty good macro growth.

Wow...what a thread! I haven't posted here before but I've sure spent all sorts of hours reading and with your help (thanks especially to Fishman's summaries!) went from DIY virgin to proudly enjoying LEDs on my nano.

Quick question: I'll be getting a small sump/fuge soon and I'd like to make a 12'' fixture to grow the macro algae. I'm thinking 6 CREE warm whites, but I'm wondering how best to drive them. Is the ELN-D that I used in my first build going to be overkill? I suppose I've got upgrade potential

Also, any experience with the red Osram 660nm I just saw on RapidLED? Maybe I could mix red/white for algae? Thanks!

 

[patmack]

Here is my set up
3 22x26 heat sinks with 40 Cree 3w XP-E's 2/1 ratio blue/white with 4 XP-G for high noon each. Total 120 leds

22x26?
To bad they don't make 18x18 that would be perfect.

 

[kcress]

Closser; Neutral White are soooOOOOoo orange that I'd suggest you use them an NOT WW as they would probably be red.

 

[Closser]

thanks patmack and kcress

 

[tonythefish]

typo 8x23 ! Was thinking of something else

 

[James77]

Just a check with everyone to be sure I am on the right track with what I am about to start.....This is for a 120 gallon, 4'x2'x2' mixed tank.

Building a fixture using 1/8" channel aluminum. Plan on using 96 LEDs, a 50/50 mix of RB and NW using 60 or 80 degree optics. I am planning on 6 rows of 16 LEDs. Side to side, LEDs will be spaced approx 2.5", front to back about 2.25" for total fixture size of about 44" x 14", which includes some space on the sides.

Will be using 2 MeanWell HLG-185-42B Drivers, each one running one set of colors....4 strings of each. Dimming will be Apex controlled, and I am planning to cool this as well with 2 4" fans. Reason for cooling is I will be encasing this in veneer oak and staining it to match the stand. THere will be an acrylic lens as well.

Anything off? Well....so far at least

 

[kcress]

Tooo much NW. It will look like you've lit your tank with candles. For that setup I think you'd want about 8 at most. The rest should be CW.

I don't see how you'll be able to drive 16 in series with a 42. Maybe you can with a 48 but I doubt it.

Make sure you design your enclosure to efficiently turn over all the air with your fans.

Protect your LEDs from spritzes.

I'd love to see your resulting enclosure.

 

[James77]

Tooo much NW. It will look like you've lit your tank with candles. For that setup I think you'd want about 8 at most. The rest should be CW.
.

OK, glad to catch that now, I have not ordered the whites yet.

I don't see how you'll be able to drive 16 in series with a 42. Maybe you can with a 48 but I doubt it.
.

I was told by Mike at RapidLED that I could do 4 strings of 12 on one driver, that is waht I am planning. One driver for blue, one for white. I hope I have that correct?

Make sure you design your enclosure to efficiently turn over all the air with your fans.
Protect your LEDs from spritzes.
I'd love to see your resulting enclosure.

Should the air be turned over from the LEDs themselve, I am planning on cooling just the channels themselves by directing the air through them. One 120mm fan for 3 channels. Yes, there will be an acrylic splashguard.

I will post photos of me building it if I can get the design out from my head into real life .

Thanks kcress!

Mikes email to me regarding these drivers:

"Since you're going with a 50/50 mix of NW/RB then I would go with 4 strings of 12 NW on one driver (the driver will output up to 1.1A, which is a good range for that LED) and those strings will be balanced. For the blues, if you're using 4 strings then you'll need to adjust the driver to output less than 4A (you can adjust the output of the driver from 2.2-4.4A) so that each string maxes out at 1A, since that's all the blues can handle. With your set-up balancing strings is quite easy actually, it only gets difficult when people try to mix various colors within a driver/string and don't have equal amounts of them in their set-up."