What wattage with Metal Halides?

[Firesole]

I'm planning on getting new lighting for my tank soon and I am trying to determine all of my options. I have thought about both T5 and MH fixtures. I am considering now building my own fixture. If I went with MH, how many bulbs and of what wattage do I need? If a can get T5 supplies would I be better off with them or MH? I currently have a 55gal tank but would like to step up to a 75 or 90 soon. Maybe even a 110 or 120 since they are all 48" long. I figured I would run 2 MH bulbs but I don't know the wattage needed. Also, I was going to attempt cutting cost by going through one of our electrical parts suppliers here at work but I'm not sure what all to tell him that I need. Another option, we stock individual housings for 500w Quartz Halogen floodlights as well. is it possible to get these bulbs in a lower wattage and the required kelvin rating??? can you list PROs and CONs to having MH, T5, and/or Quartz Halogen?

 

[fatdaddy]

It's usually 1 bulb every 2 feet. As for wattage, it depends on your tank height. I have a 110g Tall that I use 250 watts and another 100g which is wider that I use 150 watt bulbs.

I haven't tried T5's, so I can't really comment on them. However, I like the brilliant light and shimmer that comes from MH.

Part of it also depends on what you plan on keeping. Shallow specimen's will need brighter/MH lighting; however, deeper specimen's can get away with less lighting.

Also, MH generate a lot of heat, so you'll need fans in any enclosure to keep it cool. You'll also need a way to cool the water, but so far, I've been able to do this with fans blowing on the water surface.

 

[Barney_Googles]

I am not a lighting Guru, I use T5's for a smaller application but I don't think Halogen Bulbs would do what you need to do. Be careful trying to skimp because when you do, you run the risk of spending much more than you would have if you set up properly in the first place.

If there was a secret to saving money on lighting, it would be out there for all to see with all of the reefers that have tried to stick to a budget or come up with a shortcut.

 

[abulgin]

<a href=showthread.php?s=&postid=13326497#post13326497 target=_blank>Originally posted</a> by fatdaddy
Part of it also depends on what you plan on keeping. Shallow specimen's will need brighter/MH lighting; however, deeper specimen's can get away with less lighting.

I'll bet you can find a T5 tank owner that successfully keeps all kinds of shallow-water corals and clams for every MH tank owner that does the same. There have been studies posted here on RC showing that the proper number of T5s using individual reflectors can produce as much PAR at all tank depths (if not more) than MHs. It all depends on how efficient the fixture is, and how cool it runs the bulbs. The Tek fixture is not as efficient as, say, the Aquactinics fixture because it runs very hot. T5s that run hot are not as efficient as when they are run at cooler temps.

I think it comes down to personal preference. MHs are tried and true coral and clam growers, and you can get by with a lot less bulbs/fixtures than you need with T5s. True, bulb for bulb, MHs have a much greater heating effect on your water because they are point sources of light and radiate all heat downwards (whereas T5s radiate heat over the length of the bulb and in 360 degrees), but when you factor in the number of T5 bulbs you need to match MHs, I'll bet the heating difference is not much. I used to run 6 T5s on my 110g before switching to 2x250W MHs, and, although I didn't record my temps, the difference is negligible--in fact, my tank may have been hotter under the 6 T5s. But, this all depends on setup, ambient room temperature, and some other factors. Heat is definitely a valid concern with MHs.

Also, how much space do you have? Do you have room for 6 or 8 T5s? If not, then maybe 2 MHs is a better option.

Does your T5 fixture have individual reflectors? If not, it's not better than a power compact fixture and won't come close to MH in terms of performance.

Do you like the shimmering water effect? If so, you need point sources of light--T5s won't give you that.