My suggestion would be to use LED's as the white source, and stick to T5's for the blue and actinic. In units that use blue and white, the blue's are what kills the efficiency rating. The spectral plot of most blue led's is pretty much the white led with everything but the blue spike removed... so great blue output, but its not as if NOT having to produce other spectrums allows them to make THAT MUCH MORE blue light.
I posted this over at my local club's forum...
wireefsociety.com • View topic - New 300G? build thread
"Here... Cutter has the XP-G's ready to go...
Cutter Electronics
XPGWHT-L1-0000-00H51 R5 Bin
Cutter XPG 407S
(Cree 7up XPG on 40mm MCPCB. Series Wired)
That is 7 cool white XP-G's on a single chip for $47. 4 of those (28 LED's total) will match the output of a 250 watt Ushio 10,000K and use 92.4 watts.
You shouldnt need optics, but if you do, they make a 7-lenser to match... 40 degree spread, for $16.95
Cutter Electronics
This should run them...
96-Watt MagTech LED Driver - LED Supply.com
The thermal solution is up to you unless you wanted me to make another one of my liquid cooled solutions to make each unit dinky.
So for about $300 in drivers & LED's, you can replace a 250 watt halide with LED's. For blue/actinic though, I would still suppliment with T5's, although I would note that the XP-G's have a significant blue spike in them... similar looking to running a Ushio 14,000K and a pheonix 14,000K side by side. See page 3 here:
http://www.cree.com/products/pdf/XLampXP-G.pdf
If you put the optics on there, sure, it will cost a little more, but with a 40 degree spread, you could mount those things as high as you want, and they would make a very intense spot (at 3' away, that would be a 26" illuminated circle, at 4', that would be a 35" spot) . If you wanted a setup where the light was concentrated just on the corals and rock, but left the glass and corners in the dark (possibly saving you more wattage & putting what you have only where you need it), this would be the way... japanese style anyone? I should have a small test sample up and running sometime soon, although Im in no rush exactly. Interested?"
IMO, the best deal is to get the 7 LED's on a single PCB... but keep in mind that that you wont be able to skimp on the cooling solution. The efficiency of these guys does offset some of the heat production, but the higher density of having 7 LED's on a single chip means you have a higher concentration of heat to deal with. My solution before these even came out was to simply water cool, but a regular heatsink made of Al might be fine as long as you have fans running. OR, use copper instead. Making the unit water cooled would allow you to make a very compact fixture as well though... rather than having to space out the PCB's, you could cluster them together... 4 of them in about a 3"x3" area, or in about a 1.5"x6" area... you pick. You could even get creative and mount each PCB on its own heatsink normally intended for CPU cooling. OR rather, many hard drive coolers could be converted to mount the LED's on (including water cooled ones). The driver units are getting more common... AC powered current drivers in the 96watt and 150 watt range with dimmers are getting more and more common, so have a look around... you dont need a dozen buck-pucks and seperate AC/DC sources to run these things.
My test system is pretty much ready to go here... but for now, I have to plumb the water cooling through my computer's cooling array, so I have to add some connects/taps and Im still waiting on the Liang DC pump I want to use as the pump. So far, I have been using the eheim 1250's... they dont like being restricted to 3/8" cooling lines...
Think my radiator is large enough? (its that 7' tall shiny thing to the right of my computer)
