metal halide

[J. Fisher]

Does anyone here use metal halides for your planted tank? I am setting up a 125g and will be using halides. I was wondering about watage to water volume ratios. Is the ratio more or less the same as CFs?

thanks
J

 

[malkore]

technically no, MH are less efficient than CF bulbs. they are somewhere in-between incandescent and normal fluorescents. Use the traditional 'watts per gallon' guideline, and err on the side of caution...go over 3wpg to ensure enough light for all plant species if your goal is a high light/CO2 injected tank.

do you already have the halides? if so, feel free to use them, but if you're going to have to purchase them, I wouldn't bother. CF is great for 125gal tanks, and is probably going to be cheaper than MH lighting to setup and run...plus there's less heat generated.

 

[nawlins9175]

A typical MH is far less efficient than a flourescent. Upwards of 60% less efficent depending on model, so the money spent on electricity would be far greater. I would go with a T-5 or T-8 FL setup. The color and light rendering is far superior also.

 

[J. Fisher]

Thanks for the advice, very helpful!

My intention was to acheive that shimmer effect you see in reef tanks equiped with MHs. I always thought the rippling light would look great on my plants.

I have not purchased the lighting yet so I have some thinking to do. Perhaps the MH / CF combo fixtures would work well for what I am looking for.

 

[exodus]

I disagree, I think MH lighting would be great on a FW tank. I'm considering doing it myself, because even though T-5, T-8 and all those are more efficient, I believe MH lights will do a much better job at penetration to the bottom of the tank.

I'd go with 3-4 175w fixtures. You can get them on ebay and various websites as kits for pretty cheap, probably $25+ on ebay and about $38 plus from other sites.

I love the shimmering effect, but reef tanks have much stronger currents. If it works though, please let us know!

 

[exodus]

I just installed my MH lighting tonight on my tank, and it looks great. Key to getting the shimmering effect is to mount the bulb farther off the surface.

 

[J. Fisher]

Nice! You beat me to it.

I can't wait to get set up. I think I might go with three 175w retrofit kits (cheapest I can find is $200 each) This will put me at 4.2 wpg. As Malkore said this will put me in the cautious zone since I will have preasurized co2 for this setup.

I was thinking of mounting them about 12" above the surface. I am building the stand and canopy myself so I can customize the height of the lights with no problem

 

[Wizzard~Of~Ozz]

MH bulbs can't be readily compared to fluorescent.. They use an arc to produce the spectrum which is analog whereas fluorescent are almost digital.. Tri-phosphor fluorescent bulbs have 3 distinct spikes, 1 red, 1 green and 1 blue. Metal halide mor accurately reproduce the curves on the spectrum produced by the sun. they are essentially daylight in a bulb, fluorescent cannot compare to them at all, completely different style of bulb.

High performance fluorescent tubes are capable of generating the same, or even slightly more, light output per Watt than MH bulbs. In particular the Philips ADV850 operated under standard conditions even outperforms most MHs. Considering that these inexpensive T8 bulbs can be overdriven by electronic ballasts with high ballast factors (> 1), thus delivering even more light, they are possibly the best option to light a planted aquarium in terms of performance/cost factor.

So go with fluorescent if you can find a really good bulb, otherwise metal halide will beat it every time for efficiency.

quote from Here

 

[exodus]

Nice! You beat me to it.

I can't wait to get set up. I think I might go with three 175w retrofit kits (cheapest I can find is $200 each) This will put me at 4.2 wpg. As Malkore said this will put me in the cautious zone since I will have preasurized co2 for this setup.

I was thinking of mounting them about 12" above the surface. I am building the stand and canopy myself so I can customize the height of the lights with no problem

If you're building the stand and canopy, I (may have said this before), but I strongly reccommend DIY as far as the MH goes.

http://www.businesslights.com/produ...id=48&osCsid=960b6c65d3cfb4474b2229d471e87bfd

Thats exactly the ballasts I have in my canopy. Go to home depot and get yourself some sheet metal and bend yourself a reflector - you've just saved about $300.