Can I make this light work?

[Anchovy]

Sorry for so many questions! Here is the description of the light: 5 Foot 350 watt Metal Halide fixture with 2 175w 14k bulbs 48" actinic florescent bulbs, and ballasts. $200.00 obo

Pics:

My tank is only 4 feet, not 5. Would this just be a waste of light? If this light will not work is this about the right wattage I should be looking for (tank is 31 inches deep). I was looking at a similar light at DFS and it is very expensive, what is the difference between the two (besides it being used and the wattage is higher on DFS).
DFS light

 

[ct_vol]

What are you wanting to keep again??? 175w MH's aren't much for a 31" deep tank... I'm not sure you'd want it hanging over 6 inches on either end... You'll probably end up buying another setup later... FWIW I'm not a big fan of that DFS fixture either... I don't really care for PC's being used for actinics...

 

[Anchovy]

To be honest I'm not sure what I want to keep. I know that doesn't help you. Right now I really like the zoas, mushrooms, and rics. The only thing I know that I want in the future that needs a lot of light is a clam. I just don't want to have to keep upgrading the light fixture (or anything for that matter). I just want to do it right the first time. I have HO T5's on my 20 long so that is the only thing I am familiar with. I like the look of the MH hanging pendants, but would one of those be enough? What would you recommend ?

 

[ct_vol]

People have kept clams successfully under T5HO's... But you'd want to keep them in the upper half of your tank for sure should you go that route... Zoas and Mushrooms can survive in lower light conditions, but most tend to grow a bit better when they have more light...

My preference is MH with either t5 or VHO actinic supplementation...

One would be enough for about a 2 ft area... If you plan to keep all of your corals to one side or the center of the tank then thats fine... I did that for a while when I first started out... I had one pendant over my 6ft tank with Normal Output bulbs over the rest of my tank... As I could afford the new pendants, I added them... Untill I had 3...

 

[Anchovy]

That is a good idea. I could go ahead and get the pendant and the T5 fixture and get another pendant after this thing is set up. Sounds good! Thanks!

 

[Angela Short]

FWIW I had 175 MH's on the ends of my 31" deep tank and stuff grew fine on the sand. LPS, Shrooms, rics, zoas and stuff. I actually think some things prefered the lower light after I moved all mh's to 250's. If you did a clam he could be on the top of the rocks but I like the brightness of the 250's . Then the heat issues involved with 250's is something to think about also but if you are doing hanging pendents that will help heat a ton since canopys hold heat.

 

[EvilMel]

I'm a fan of having different areas of light around the tank too.

When I had the 6' tank, I had two 400W MH bulbs, spaced such that there was a bit of a darker spot in the middle. I did this on purpose when I first chose my lights so that I could place lower light stuff near the top in that section if I wanted to. I had a Rose Leather that absolutely THRIVED there.

I also placed my MH bulbs perpendicular to the tank rather than parallel. If you think about the way the light spreads out, it will spread farther off the sides of the bulb than the end (one end is the socket even!). SO think about that as well.

I always see these fixtures like you showed and wonder why the bulbs are placed in a parallel orientation rather than a perpendicular one.

ALSO, IMO you should be looking for 400W lights, 250Ws at the minimum. You always want to err on the side of too much light rather than not enough and with a 31" tank...you're gonna need those 400s (if you ask me). I could be wrong but it would make life certainly easier.

 

[Anchovy]

Would that be 400 total or between the T5s and the MH or just the MH's?