Update time! Cleaned up excess wiring & secured it to safely continue using the fixture. So far it's working great with no duds & I'm able to blend/control the colours nicely with the 3 dimmers. I've ordered 2 more dimmers to split the 6000K whites from the 10000Ks. I'll be ordering at least two more power supplies to distribute the load & run each colour on a separate timer. The current config works fine until those parts are in, it simply means I need to manually adjust the intensity for dawn/dusk dimming every day. Colours on separate timers will allow basic dawn/dusk effect, but automatic dimming using additional electronics is something I'm contemplating for the future.
12VDC, 250watt power supply & three 8amp dimmers are now mounted on a board in the center compartment of the stand. Another dimmer will be added to isolate the 6000K whites from the 10000K whites. 14AWG single strand house wiring runs from power supply to dimmers. From dimmers up to fixture is 14AWG stranded hook up wire.
Top side of the fixture. Added 4 cedar slats to mount terminal boards for wire distribution. Drilled additional holes in the rails for rubber grommets to feed LED wires thru.
Ten of these 12 to 24VDC, 900mA constant current drivers for 10watt LEDs came in last week. Don't think I'll be using them on this fixture since there doesn't appear to be any adjustment on them. I test fired one on a spare 10watt LED & it worked great at regulating the current as advertised. Haven't tried running it downstream of a dimmer to see how it reacts to that, but even if it works, I'd need one for every LED & that would be a bunch more hardware to add to the fixture. Since the build is essentially a parallel hookup, with each LED seeing the same voltage as delivered by the dimmers, constant current is less of a requirement than for a series application where you're feeding a string of LEDs. They might still come in handy for when I set up a fuge or frag tank, since there's really no dimming requirement for those applications.
Photo taken last night directly at the LEDs. Don't recall what voltage I was running them at, but nowhere near max. & they were still very bright.
Had to run the two 250watt 14000K MH Plusrites yesterday while I was completing work on the LED fixture, so here's a tank shot to compare with the LED photo from last week. MH
and the LEDs. Nicer spectrum & more pleasing to the eye to me. Better blend overall & still underdriven. Not too shabby at less than half the power consumption of the Halides.
Very happy with how it's turned out & livestock appears to be adjusting without issues. Female Maroon clownfish spawned a couple days ago, so she's clearly ok with it. Will take some time until I know how the coral fares, but everything looks quite happy after a week under the LEDs. Have 7 Blue & 2 Royal Blues left over from the build, along with miscellaneous wiring, hardware & resistors I didn't use. The fixture easily lights a 4 foot tank, weighs only around 7 pounds & the cost of material is somewhere in the neighbourhood of $600 to $700.