How much Metal Halide for my 54 corner?

[jethro]

I have a 54 gallon corner tank that I just set up.
I am thinking about making my own metal halide fixture.

How much wattage and what color of lighting is recommended?

Thanks

 

[Robin Goodfellow]

hi.
Either 175W or a 250W will be enough, I feel.

Color will depends on rather you will go excusively MH, or you will use PC or VHO for actinic.

 

[jethro]

Two more questions....

What about the heat?

Are they a fire hazard?

My wife and I both work and the lights will be on while we aren't home.

 

[wetworx101]

I use a 400w MH on my 60 cube (similar tank), with 10,000k bulb and no actinic. Awesome results. I do suspend it almost a foot above the tank however.

 

[jethro]

There is another question?

How close to the water do I place the light?

If you have a 400watt bulb one foot over the water, why not a 100 watt bulb a inch or so above the water?

How does this work?

 

[wetworx101]

Uh, no. The purpose of the light being so far off the water is so I can keep the tank from absorbing too much heat. The other reason is that I have some shrooms growing at the bottom of the tank, and so I manipulated the height to change the intensity enough to allow them to grow as well as my clams and sps corals which are higher in the tank. Some might argue that I could have a light that is only 6" from the surface and 175watts, but then I would be limited in what I keep (usually, and if it wasnt for the shrooms, I would have it at 8" clearance). I will admit, the 400watter could go as close as 8" from ther surface, my shrooms didnt like it though. With MH, you just dont want to get much closer to the water than 8". Sea-spray ends up all over the bulb, evaporation increases if the top is open, it heats up the tank, etc. Im just letting you know that a 400watter would work, and then you will have enough light to grow whatever you want.

 

[jethro]

What about safety?

When I was at "the electrical dealer" the subject came up about how the bulbs had been known to explode. He showed me the newer bulbs that have a protective coating.

It was a 100w bulb for only $20. He commented about how "those pet outfits will charge you 3-4 times as much for the same bulb.


From what i have learned, the higher the wattage for the bulb, the more I will have to pay for a ballast to run the bulb.

Is 100watts not enought?

I used to only run two 40watt florescent tubes and had awesome coraline.
Never had corals yet.

 

[apparent]

I think coraline grows best under lower light not 100% sure on that though

 

[Anonymous]

Most people keep their mh at around 10 to 12 inches above the water, for heat and for safety(bulb exploding). Plus then you can work on your tank with the lights on. That salesmen is most likely wrong, check the specs of the bulb, CRI and kelvin rating are a good place to start.

I had a 54 corner, I used 4x 55w pc, but I really should have used 1x 175w mh with 2x 28w pc actinic pendant.

Gresham