constant current or dimable?

[they call me bruce]

Here' Here' we do have a "plethora of choices" Thanks Redfish & Hoppy for all the help I think Im ready for this build Guess Ill buy the Lamborghini and drive like an angel !
Ill draw up the plans today and post them here --for one last scrutiny
Thanks again

[they call me bruce]

Redfish your right; i forgot about the spreader bars i have to find out if there is 1 or 2 on a 72" long tank

[Milad LEDGroupBuy.com]

Just to add to the comments.

48 XM-L LEDs on a 72in tank at 700mA is ALOT OF LIGHT. Dont kid your self that you need to max them out.

Just stick with 4x http://www.ledgroupbuy.com/inventron...-driver-700ma/

Its simple, no tuning, no blowing up your LEDs because meanwell wants you to open upt he driver and fiddle with a screw, easy.

And since it comes with a reference voltage, you just throw in a pot: http://www.ledgroupbuy.com/10k-ohm-1...r-easy-solder/ and you are off to the races. The pot will let you dim the LEDs because you will end up noticing its too much light.

[they call me bruce]

thanks milad I final thought the light will be about 8-10 inches above the water level in a 28 inch tall tank will 40 degree optics do ok? dont want spotting

[tentacles]

Well it depends on spacing as well, but for example i am using 60 deg optics 12" above substrate with 5" spacingide to side, front to back spacing is like 4" maybe. I suggest buying two options for optics, I found both times buying LEDs (got some cheap ones from aquastyleonline and cree from cutter) that the optics vary more than you'd like. For example, the pattern on the 45 deg optics i got from cutter was terrible with strange artifacts instead of a smooth spread. The 60 deg optics are fantastic. And the 80 deg optics from aquastyle just didn't seem anywhere near as bright, with a LOT more side spill than the 60.

I had a thought of using really narrow optics, like 5 degree, and mounting the LEDs recessed in (narrow) matte black tubes in the ceiling, but you'd certainly need to do some experimenting with spread and height etc to get a nice tight pool of light over the tank. But you could have "invisible" lights, although the fixture and tank would be specific to each other and rather troublesome to move. I'm going to try and get my hands on some narrow optics to try this soon-ish

[they call me bruce]

i was looking at a few different charts, looks like with two rows of 40 degree optics should do the job covering the tank with enough overlap that there will be no spoting

[they call me bruce]

Update changed the plans a bit the tank is now 72x24x24 thats the final change ill have to live with it
so that means 3 rows of xmls cool white and nuetral light mixed with 60 degree optics about 10 inches off the water of course some blues mixed in for night light
I think the 48 total lights is way to much so i have to rethink that one