Talk to me about Cree XM-L LED's

[WickedBlue28]

Seems they have been on the market for a year now. Anyone use them? Pros and cons to other set ups? Are the colors similar to the XP-G

[nanojg]

I run the xml neutrals on my 90s, they are very powerful, I run some at 1.75 amps for a about 3 hours a day and the rest at about 1 amp for 10 hours. Most efficient and powerful led out right now. You can look at the data sheet to compare colors. I run the xpg cool whites on my other tank so cant really compare those to the xml neutrals. For me a 1:2.5 ratio of xml neutrals to royal blues is perfect.

[WickedBlue28]

I've got a JBJ NanoCube 28g and was planning on running this:

8 Cree XT-E RB
4 Cree XP-E Blues
6 Cree XM-L NW
6 Cree XM-L CW

What do you think about that mix?

[nanojg]

I think xmls are a waste of money on that tank, unless the fixture will be very, very high. I run my leds on my 24 nanocube at about .4 amps, at that low current you will be just fine with the xpg whites. I dont know anything about the blues, I run cool whites and royal blues on my nano at 1:1 and nw and rbs on my 90 gallon at 1:2.5, I much prefer the neutral whites to the cool whites. Personally I would ditch the cool whites and do just neutrals as far as whites.

[mussel and hate]

The only downside is expense. If that is no obstacle to you I can't think of any reason not to use XM-L.

Your ratio doesn't comform to the norm but that is a matter of personal preference. Perhaps you prefer less of a blue look.

[WickedBlue28]

The extra expense of the XM-L's is not a concern in my particular case.

I'll be using a Inventronics 40w driver - 700mA driver rated for 15 LED's.

How about if I add 3 more blues? I'll have extra.

Perhaps this ratio would give me a better look without having to turn the whites down

11 Cree XT-E RB
4 Cree XP-E Blues
6 Cree XM-L NW
6 Cree XM-L CW

[nanojg]

Originally Posted by WickedBlue28

The extra expense of the XM-L's is not a concern in my particular case.

I'll be using a Inventronics 40w driver - 700mA driver rated for 15 LED's.

How about if I add 3 more blues? I'll have extra.

Perhaps this ratio would give me a better look without having to turn the whites down

11 Cree XT-E RB
4 Cree XP-E Blues
6 Cree XM-L NW
6 Cree XM-L CW

That combination will give a white with a yellow tint IMO

[WickedBlue28]

thank you for your imput.

What would you suggest?
I have 12RB 6B 6CW 6NW

Drop some of the CW's?
12RB
3Blue
6NW
4CW

[nanojg]

Run em all if you already have them! You will just have to drive the blues at a higher current than the whites for a more pleasing look imo

[WickedBlue28]

I'd run all 18RB/B's but the driver I'm using is only good for a 15 LED string correct?

[nanojg]

Originally Posted by WickedBlue28

I'd run all 18RB/B's but the driver I'm using is only good for a 15 LED string correct?

In that case I would do:

3-4 blues
11-12 rbs

6 cw
4 nw

[nanojg]

Originally Posted by WickedBlue28

I'd run all 18RB/B's but the driver I'm using is only good for a 15 LED string correct?

Dp

[WickedBlue28]

Really more Cw's? I thought the thrend was less CW's and more NW's

[nanojg]

I prefer nw, but its all about balance, the nw are a very broad spectrum and produce a lot more yellow light. You need 2+ blue leds to balance out one nw imo

I use only nw and rb in my 90 gallon and love it (1:2.5)

[WickedBlue28]

I gotcha hence the 2:1 ratio everyone talks about.

So
Option #1
12 RB 3B 6CW(XM-L) 4NW(XM-L)

or
Option #2
11RB 4B 6CW(XM-L) 4NW(XM-L)

[nanojg]

I like option 2 (although Im guessing, i havent tried the blues)

Here is my "led math," not sure if it makes sense though

CW:RB/B ratio = 1:1
NW:RB/B ratio = 1:2.5

If you have 15 RB/Bs then you can get close to balancing that equation by adding 4 nw and 6 CW:

15 RB/Bs = 16 whites (4 x 2.5 NW) + 6 CW

[WickedBlue28]

Interesting.

Maybe option 1 would be a safer bet than 2 because the RB and more accepted than the Blue

[jameshongth]

iirc.. 1:2 ratio are refer to both the NW and RB LED running at the same current(amp) to obtain 14kk.

If you are running XML at 2100mA and assume RB driving at 700mA then the ratio will have to shift from 1:2 to either 1:4 or 1:5 combination inorder to have the same colour temperature like the above.

[ari5736]

What drivers are people using to drive them to 2.5-3A?