I'm trying to decide how far above the water I need to mount my fixture and I need advice! My tank is 72 x 30 x 24 tall and I will be using 3 x 400 watt metal halides with 14k bulbs. There is glass between the reflector and the water to prevent splash damage. I would like to be able to have clams on the sand bed and sps to about 18" deep. Thanks!!
Lighting Question
- Thread starter dubaygv
- Start date
Thanks!
Tomoko Schum
New member
Do you have a glass sheet over a tank or do you have a metal halide fixture with a built-in glass cover? I would not recommend a glass top over a tank since it will keep the heat in.
I have three 250W 14K MH lamps over my 180 without a glass top and never had any issue with a splash hitting a lamp. My lamps are suspended about 14 inches above the water surface. A crocea clam, which I lost recently when a big rock dropped on it, was happy and growing on the bottom of my tank with a 250W MH lamp above it (I had it for at least 6 years.)
In the case you have not purchased a light fixture yet, 250W lamps, combined with high performance reflectors such as Lumenbright or Lumenmax elite, are supposed to be sufficient for a 24 inch deep tank (according to Dr. Sanjay Joshi.)
With your tank being 30 inches deep front to back, you need to suspend your fixture somewhat higher to cover the 30 inch wide area. This may necessitate the use of 400W to really color up some of your light demanding SPS's that are placed lower than midway in your tank if your reflector is not a high performance type (the likes of Lumenbright and Lumenmax Elite). Lumenbright wide coveres 30W area, though.
I have three 250W 14K MH lamps over my 180 without a glass top and never had any issue with a splash hitting a lamp. My lamps are suspended about 14 inches above the water surface. A crocea clam, which I lost recently when a big rock dropped on it, was happy and growing on the bottom of my tank with a 250W MH lamp above it (I had it for at least 6 years.)
In the case you have not purchased a light fixture yet, 250W lamps, combined with high performance reflectors such as Lumenbright or Lumenmax elite, are supposed to be sufficient for a 24 inch deep tank (according to Dr. Sanjay Joshi.)
With your tank being 30 inches deep front to back, you need to suspend your fixture somewhat higher to cover the 30 inch wide area. This may necessitate the use of 400W to really color up some of your light demanding SPS's that are placed lower than midway in your tank if your reflector is not a high performance type (the likes of Lumenbright and Lumenmax Elite). Lumenbright wide coveres 30W area, though.
The tank is an older acrylic with quite a bit of bracing around the edges. I have acrylic top pieces that fit in the open spaces but I'm not sure that I'll use them. I have a 150 gal rubbermaid sump that's plumbed through a wall into a spare bedroom so hopefully I'll be able to dissipate the heat from the lights. The ballasts are CoralVue dimmable electronic ballasts with LumenBright reflectors. They are sitting on an aluminum frame. The frame has glass between the reflectors and the top of the tank.
This is a bad pic of the fixture but shows how the lights are sitting on the frame and the Ice Cap ballasts are no longer there.
This is a bad pic of the fixture but shows how the lights are sitting on the frame and the Ice Cap ballasts are no longer there.
Tomoko Schum
New member
That will be an awesome set up. I love the aluminum frame for the lights. Did you make it yourself?
I would suspend that light fixture high up if you are going to use 400W bulbs.
I would suspend that light fixture high up if you are going to use 400W bulbs.
I wish I could have made it, but I bought it from a guy in the Atlanta Reef Club. Right now the bulbs will be about 22" above the water. Is that too close? I could always run the ballasts at 75%.
holy cow! that looks AUsome
Thanks and War Eagle! (although we don't have much to cheer about this year) Did you get the rest of the 120 setup from Gary yet?
Tomoko Schum
New member
I would like to make a rack like yours. I have the necessary step-by-step instructions from a couple of websites and the link to the manufacturer of the tubing. The manufacturer will supposedly cut the materials to my specification. I need to take some measurements inside my canopy and get going...
I'd start by mounting the rack high up and then bring it down slowly. 22 inches sounds okay to me as an initial height, but your light may spread beyond your tank unless you have a full canopy. You can gradually bring down the light fixture by looking at the color of your corals or set it at the right height based on PAR readings if you have an access to a PAR meter.
I'd start by mounting the rack high up and then bring it down slowly. 22 inches sounds okay to me as an initial height, but your light may spread beyond your tank unless you have a full canopy. You can gradually bring down the light fixture by looking at the color of your corals or set it at the right height based on PAR readings if you have an access to a PAR meter.
I won't have a full canopy, but the sides will be covered so hopefully there won't be too much light escape to the sides. I'm going to leave the top open for air movement though. I'm working on building it now, but before I paint I'll check the light spread. Unfortunately I don't have access to a par meter.
Tomoko Schum
New member
Looking very nice! Keep the pictures coming.
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