# Advantages of metal halide?



## SunnyIL (Mar 22, 2004)

Okay, I searched for this and I couldn't quite find a discussion on this topic (maybe I'm searching improperly).

Are there any advantages to metal halide? The reason I'm asking is because a pendant fixture would fit really nicely for my new Oceanic 30 cube ... one reason being aesthetic, but the cube is a little "back heavy" (i.e., where the lights would go). I'm still not sure any fixtures are exactly what I'm looking for. I feel a pendant would be a better distribution of light. However, the halide fixtures are like 175 W, which I'm gathering would be way too much for a 30G ... or not ... do I merely take the light up higher?

But overall, is halide a 'better' light for planted tanks, about the same, substandard, etc.?

Thanks!


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## rkundla (Mar 25, 2004)

A 175W pendant right on top of your cube would be overkill. The higher you raise the pendant over the tank, the more the point source light spreads out from the pendant, the less light energy that reaches the interior of the tank. 

If you want half the light energy reaching the tank, you would probably put the lamp 12-16" from the top of the tank. Only negative is that you would get a lot of light spillage outside the tank, so don't sit low near that light or else you will get blinded. :wink: 

Suspended metal halide does present a clean look, espeically with that Oceanic cube -- very classy.

Is metal halide better than CF? No. Is it worse than CF? No. Each has its pluses and minuses. I like metal halide because of the ripple effect and the fact that it has a noticeable fall-off of light from the center outward. I can 'focus' the light on light hungry plants in the center and put lower light plants out on the perimeter. CF provides uniform lighting across the length of the bulb, so the intensity is the same where ever you look.

Ron


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## GDominy (Jul 30, 2002)

You can't really say if one is better or worse then the other.. they are different, most certainly.

I don't believe a 175 watt pendant would be overkill at all. Pendant lights, while attractive looking, loose a lot of light due to the shape of the bulb and reflector. Not a big deal at all for a planted tank of your size though. 

rkundla makes several good points though.. and I think that the classy look of a pendant light over that tank would simply be stunning.

From a purely visual point of view there is nothing that can compare to the intense natural looking beauty of raw non-diffused light. You get the rippling of the light across the bottom of the tank, a very pure natural light that casts shadows... I personally love it.


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## rumples riot (May 29, 2003)

Like others I think that there are some advantages to Metal Halides.

First, the light from a metal halide will closely resemble the light intensity of the Sun. This is important for growth of plants, especially those that are growing on the substrate.

Second, Metal halides are really useful in taller tanks as the light will penetrate deeper than CF lighting. This is related to the point above, but more to do with owning deeper tanks and being able to grow large plants and carpet plants at the same time.

Third, metal halides are supposed to produce much more compact growth of plants, although I must say that this really depends on the plant, fertiliser type and amounts involved. It has been my experience that some plants like ambulia will always tend to get long internode lengths despite intensity of light.

Fourth, I have noticed since getting metal halides my plants contantly produce streams of bubbles under the lights, where as before under 2.6 watts per gallon of CF lights they would only do this after a water change. This streaming does wonders to the health of your fish and your bacterial filtration. Fish will become extremely resistant to disease in a high oxygen environment where they can breathe easily. They will be less stressed and act more naturally in such conditions.

Fifth, they are useful in maintenance of a tank. Because they are set up higher you can easily access your tank at any time to do maintenance.

Sixth, they do look very classy, but they will use more power, not much more.

Finally the light will reach every nook and cranny and therefore allow you to grow some of the more difficult plants that CF lighting will struggle with.

These are points are based on my own experience and I welcome any other points of view to the debate.

Paul


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## Knetter (Nov 4, 2003)

Paul, I totaly agree with you. I have mh too above my tank. The shiny effect from the water ripple is soo nice!


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## SunnyIL (Mar 22, 2004)

Thanks everyone - especially Paul for explaining the differences. Being a newbie, it's kind of hard to find things broken down as to the "why" of things ... though I really enjoy everyone's divergent opinions!

I ended up going with the MH because it's just so beautiful (and from what I learned, is good for the plants and fish too). I just couldn't walk away from that reef tank at the store w/it. The ballast was on back order though, so have to wait until next week to get the light on. I constructed everything to hang it alreayd. My tank, though small, is a big focal point in my living room, so it was worth the extra money to me. 

Part of setting my tank up is therapeutic. I fell down a flight of stairs and am rehabbing physically (and now might need cervical fusion surgery), so I just wanted it to be as beautiful and amazing as possible ... so I can sit and escape in front of it from time to time


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## rumples riot (May 29, 2003)

Welcome to the club, the metal halide club. I see that you might also qualify for the Eheim Pimp club being an Eheim owner, we have a thread going at the moment, which you might want to join and sing the prasies of the mighty Eheim.

Best of luck with the MH's and your convalescing.

Paul


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## TeeItUp (Mar 18, 2004)

Knetter said:


> Paul, I totaly agree with you. I have mh too above my tank. The shiny effect from the water ripple is soo nice!


I have to agree too. May not be much of an advantage but I love the look in my Reef Tank.


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## Fishysan (Apr 8, 2004)

I'm torn myself, I just bought a tank setup to make as a planted tank and have two 55w PC lights for a 55gal corner bow. To think it came with an 18w FL!! I wanted to go simple & drop & play. Maybe I should return em and use a 175w MH - have them kicking around from reef upgrades. Hmmm. Didn't want to have to deal with the extra heat & electricity, but now I'm thinking that 110w of PC over the 55gal isn't enough for a medium light plant tank. (2wpg)

And I thought light debates were just for reefs! HA! 

What MH bulb are you guys using? Hydroponic shop ones? Venture 5500k? I don't think I would want to use less than 5000k - to yellow.

Thanks..


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## rumples riot (May 29, 2003)

I am using 5700k lamps in a aquastarlight future setp.


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## rkundla (Mar 25, 2004)

Fishysan said:


> I'm torn myself, I just bought a tank setup to make as a planted tank and have two 55w PC lights for a 55gal corner bow. To think it came with an 18w FL!! I wanted to go simple & drop & play. Maybe I should return em and use a 175w MH - have them kicking around from reef upgrades. Hmmm. Didn't want to have to deal with the extra heat & electricity, but now I'm thinking that 110w of PC over the 55gal isn't enough for a medium light plant tank. (2wpg)


I had a 54gal corner and it *definately* needs intense light because of how deep it is. I put a CSL Prism Pendant (175W MH and two 32W CF) mounted on a wood frame and inch above the glass. It helped me grow plants (wide variety, first real serious experiment with plants) a lot better than the CSL 2x65W CF fixture I had up there before.



Fishysan said:


> What MH bulb are you guys using? Hydroponic shop ones? Venture 5500k? I don't think I would want to use less than 5000k - to yellow.


I have used an AB 10000K bulb (crisp and white), a Venture 5500K (very yello, needed actinic/blue supplement to get it to a shade I preferred) and the last one was a CoralVue 6500K, which looks slightly yellowy white. 

I changed out my fixture to a 2x150 AquaMedic when I got my 75 gallon tank. It has Ushio 10000K in it now (I think). I just got my two CoralVue 6500K HQI bulbs but haven't installed them yet.

Ron


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## Fishysan (Apr 8, 2004)

Sweet, thanks Ron, showing my gf the post..  trying to convince her to go with a pendant vs. the two 55w PC hoods. I think it's the way to go. Interestingly enough, I have 3 of the 250w HQI PFO mini pendants over my reef. I'd use a 150w one of those over this puppy. 150w Double Ended would be very efficent, maybe too much? It's the equivalent of maybe 250w mogul because of the reflector & design.. 
Hmm.

Be interested in seeing what you think of the CoralVue 6500k for a planted. The AB 10000K are very nice over the reef..


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## IUnknown (Feb 5, 2003)

So what do people recommend over a planted tank with MH, 6,500K or 10,000 K?


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## Gomer (Aug 14, 2003)

well...this thread re-sparked my desire for MH *L*

so...would a 70watt HQI be a better option over a 30g oceanic then?


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## GDominy (Jul 30, 2002)

IUnknown said:


> So what do people recommend over a planted tank with MH, 6,500K or 10,000 K?


Ok... this is strictly a personal preference.. but I like bluer light.. I always have.. So I would lean towards 10,000k. If I were you I would go look at some lights at the fish stores and see if you can get a comparison.. that way you can see the visible differences first hand


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## IUnknown (Feb 5, 2003)

Gomer, luis has a great 30 cube with 150 over it,
http://www.aquaticplantcentral.com/forum/viewtopic.php?t=357

From what I have been reading combo is the best bet. 6,500K are best for plant growth, but they get very yellow as the bulb wears out. Maybe adding a couple of 13 watt 10,000K bulbs. I've put in a quote to petsupply to see if they could do it.
http://www.petsupplyliquidator.com/htm/aprod_hood_mhpc.htm


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## Gomer (Aug 14, 2003)

what if you didn't want the intense growth of 150watts? would the 70 pendent work?


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## IUnknown (Feb 5, 2003)

After doing some research, I think that is what I am going to go for. 70 watt 6,500K with 2 x 28 (I'm only going to use one bulb). The 28watt is to adjust the color so it doesn't look green.
http://www.pfolighting.com/new pfoAq/AQFrames.htm
another thing I might consider is doing 70 watt with 55 watt to use the GE bulbs that everyone likes. Still looking into things.


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## GDominy (Jul 30, 2002)

That is a combo I was considering!

I need a bit more light in my 135 Gallon tank and I figured out a way to get pretty creative with my lighting...


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## loachman (Jan 5, 2004)

hey sorry to uncover old posts... but I was searching for info on MH lights... and I'm trying to plan a new 55 gallon planted tank ... I was wondering if I could put 2 mh over it... cause it's 48 inches long, and have 2 175 watt mh fixtures over it??

that would be fine right?


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## GDominy (Jul 30, 2002)

oh yeah.. that would be great! Nice and bright


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## loachman (Jan 5, 2004)

ok .. perfect.. thanks

would these be ok?

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&category=46314&item=4305031883&rd=1


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## rkundla (Mar 25, 2004)

Fishysan said:


> Be interested in seeing what you think of the CoralVue 6500k for a planted. The AB 10000K are very nice over the reef..


The CoralVue 6500K seem to be working well in my tank. I will see if I can get a picture off today. I need to do some serious trimming in the tank and I can't seem to make quality time to do it. Maybe next weekend or when it rains so I don't have to do exterior plant trimming!  

Ron


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## rkundla (Mar 25, 2004)

loachman said:


> ok .. perfect.. thanks
> 
> would these be ok?
> 
> http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&category=46314&item=4305031883&rd=1


If you don't mind the industrial warehouse look. ;-)

Those light bays are pretty big and ungainly. I would go with a pieces-parts setup, reflectors with sockets, remote ballasts, etc... Do you have your own canopy or do you plan to hang the lights from the ceiling?


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