How high to hang lights?

bkhunt · Feb 25, 2014

I am waiting for my Chinese LED units to arrive at the first of next week for my standard 90g. I am looking for recommendation on how high to position them and how to support/hang them over my tank. Lets see you photos of how you have yours over your tank.

I am thinking on getting some 2ft supports an a 4ft wire closet shelf and hanging the light from that using S-Hooks. With the S-Hooks I can slide the lights back when I need to get in the tank. I would be able to adjust the height of the lights by moving the shelf up or down. I would also build a wood frame that I can hang around the edge of the shelf to make it look like a canopy but can easily be removed for access.

reefwatcher · Feb 25, 2014

About 6 to 8 inches

mike007 · Feb 25, 2014

I would recommend starting out at 2 ' and leave them for several weeks and see how corals acclimate then you can lower them slowly. I have mine at about 18 inches above water line. You will just have to experiment until you get the desired results.

saltfishguy18 · Feb 25, 2014

I had these chinese LEDs over my standard 90 gallon for about 10 months. I used the plant hanger kit whit is basically a plant hook with a butterfly bolt in the ceiling to hold the weight of the light. I bought simple jack chain at my local hard wear store to use to hang. I had them mounted about 5-6 inches off the water

bkhunt · Feb 25, 2014

I am unable to do the hook in the ceiling because it is in my basement with a drop ceiling.

Eckolancer · Feb 25, 2014

With a Drop ceiling you could run a wire through a small drilled hole. Have it attached to studs above the dropped ceiling.

bkhunt · Mar 1, 2014

Well I got my lights and got them mounted yesterday. I went with the wire closet shelf and hung the lights with S hooks. The lights are currently 9" above the water. I had them higher but I that gave me a large dark spot under the center brace. I still have a slight dark spot under the center brace and am thinking of moving the lights more to the outer edges and adding one more S hook so the lights are tilted toward the center. The light are currently set with the whites as low as they will go and the blues at about 25% of the range of motion of the dimmer.

trido · Mar 1, 2014

My Evergrow fixtures are 16" above the water and run at 75%. My tank is 30" deep and I have SPS all the way to the bottom.

Ron Reefman · Mar 3, 2014

mike007 said:
I would recommend starting out at 2 ' and leave them for several weeks and see how corals acclimate then you can lower them slowly. I have mine at about 18 inches above water line. You will just have to experiment until you get the desired results.

Mike, this is so old school it's crazy. And it's a lot more work than you need to do! Any led fixture worth the money you pay these days have dimmers! No need to raise or lower them, that was the way it was done 2 years ago.

To the OP, height off the water should be determined by how well the light fills the bottom of the tank. You want light to just start to spill outside the base of the tank. If it spills out more than just a little bit, you are wasting light. Raise it higher for a bigger footprint of light or lower for a smaller footprint. I wouldn't go less than about 6" to avoid salt spray and for ease of working in the tank.