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View Full Version : 20" LED fixture over 36" tank?


perpetual98
12/06/2011, 12:30 PM
So rooting around in my pile of reef stuff I found a pendant that I made 5 or 6 years ago. The opening on the bottom is 20" x 11.5". I actually used to have a SE 250W halide in it with some CF bulbs for supplement. If memory serves, I used to have it over a 20L nano tank. It's also got two 80mm computer fans blowing through the pendant. One in one side, the other blows out the other side. They also light up blue. Not sure what I was thinking back then. :)

Cutting to the chase, I gutted the reflectors out of it and cleaned it up a bit and was wondering what I could do with it. I think it looks pretty nice, but the tank that I have set up now is a 40B that is 36" wide. Would it be possible to use this pendant if I DIY'd some LED lighting into it, or would the edges of the tank be too far out and dark(er)?

MADtanks
12/06/2011, 01:33 PM
in my experience it will deff cover a 36" area.... depending on the optics you may have just a bit of dark spot towards the edge of the tank but otherwise it will be just fine.

36X30X18 with a 22X8 heatsink
http://i1201.photobucket.com/albums/bb358/myreefPM/36X30X18%20Reef/IMG_20101121_130509.jpg

It was rocking a 60/40 mix of XRE(RB)/XPG(CW) 48LED's with a mix of 70* and 65* optics.... plenty of coverage, only thing i noticed was that the SPS on the outer edge would color up were the light was hitting it obviously and ont he left side of the SPS it would be more on the tanish side, instead of deep rich color it was towards the center.

Hope that helps.

MADtanks
12/06/2011, 01:38 PM
Right before moving to my new home, i ended up scoring an IceCap fixture that i was able to gut, and here was the end result....
http://i1201.photobucket.com/albums/bb358/myreefPM/36X30X18%20Reef/IMG_7232.jpg
which made the tank look like this:
http://i1201.photobucket.com/albums/bb358/myreefPM/36X30X18%20Reef/FTS.jpg

perpetual98
12/06/2011, 01:40 PM
Cool, thanks for the info. I've never heard of a tank with those dimensions, it sounds cool.

So you're saying that the SPS on the edges of the tank (furthest from the LED/heatsink) just didn't have the color of the SPS that were directly under the lights? I would think if that was the case, just make sure I had lower light requiring corals on the edges.

I have a 4x39W T5 setup now (with 54W ballasts) and just installed new bulbs, so I'm not in any particular hurry to get into LED anyway, but saw the fixture and it got the gears in my head turning.

The one thing I'm concerned with is the fact that the tank is kinda in the peripheral vision when we're watching TV and am wondering if the pendant is mounted above the tank if we're just going to be blinded when trying to watch TV due to spillover.

MADtanks
12/06/2011, 01:46 PM
If you look at my last post, last pic... you can see the chips acro(left side on the flat/front rock) the side that is closer to the center looks green(was neon) and then towards the left looks more tan than green.... the tips purple. It will still color up just not the left side, or right side of the corals.

As far as the periphial vision thing.... really it depends on the optics. In that tank the spill was ver minimal, the optics keep the light from going all over and keeps it focust into the water vs your face ahah. Without the optics you will be looking at around 120* tipically. But to really get the light in there you will want 80* optics(around 6" from the water whre i had mine) or like 60* optics(12" height is good) that will keep most of the light in the tank and have enough punch power to get to the bottom of the tank.

GL

BigAirHarper
02/02/2012, 10:13 AM
I know this is an older post but I just found it and had a quick question, how high is your fixture off the water? And I'm looking at a 24" led fixture over a 36" tank and was wondering what optics you would recommend if I wanted to hang it from 8-12" off the surface so I could get as much spread around the tank as possible. I was thinking 90 degree.