Good and bad of a Metal Halide lamp

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torontofc

Aquarium Advice Activist
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Jan 9, 2010
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Toronto, Ontario, Canada
I just ordered a halide lamp for my red sea max 130, anyone know any problems it would cause? Is it safe to use? How many watts would classify it as a good lamp enough to maintain a high light coral. (hard coral, clams?). And last bus not least, average of how much should I pay for an 24' MH fixture? Thanks.
 
They are safe to use and offer the most realistic lighting for reef tanks. The only cons about the lamps is that they run hot which can raise tank temp (possibly need to invest in a chiller ~$400), and they use a lot more electricity. They will maintain SPS (high light) corals and high light clams, but if you want them to grow, you have to get actinic lights. A MH lighting fixture can run around $200-300, whereas a MH + T5 actinics fixture are around $500.

All corals don't require the same amount of lighting, so make sure you focus on how many watts per gallon is needed when purchasing certain corals.

high light (SPS; clams) = 5-8wpg
med light = 3-5wpg
low light = <3wpg

You can keep several corals with different lighting requirements in your tank as long as you place them correctly; such as high light corals on top, and low light on the bottom.

If the tank you have is 34 gallons, you can get away with having 1 250w MH, but make sure it's high enough or it will cook/bleach all of your corals. How deep is your tank (water surface to sandbed)? The size of the bulb may only need to be 150w if you have a deep sand bed.
 
that's not true about the actinic lighting. all of the bulbs we use are full spectrum and actinic supplement is not needed. the amount of actinic lighting people use over their tanks is far more than needed.
watts per gallon is a poor gauge to go by. it will depend on the distance from the bulb to the coral in question.
for a 34 gallon tank i agree that a 250 watt halide would be a good option.
i wouldn't use a 150 over a 34 gallon tank that housed high light corals, such as acropora.
 
The biggest draw back for MH is the cost of replacement bulbs, they cost more to run and run hotter. The upside you can usually grow about any coral, clam, or anemone, and the shimmer.
 
that's not true about the actinic lighting. all of the bulbs we use are full spectrum and actinic supplement is not needed.

I didn't know that. So you can get away with a MH and no actinics?
 
They are safe to use and offer the most realistic lighting for reef tanks. The only cons about the lamps is that they run hot which can raise tank temp (possibly need to invest in a chiller ~$400), and they use a lot more electricity. They will maintain SPS (high light) corals and high light clams, but if you want them to grow, you have to get actinic lights. A MH lighting fixture can run around $200-300, whereas a MH + T5 actinics fixture are around $500.

All corals don't require the same amount of lighting, so make sure you focus on how many watts per gallon is needed when purchasing certain corals.

high light (SPS; clams) = 5-8wpg
med light = 3-5wpg
low light = <3wpg

You can keep several corals with different lighting requirements in your tank as long as you place them correctly; such as high light corals on top, and low light on the bottom.

If the tank you have is 34 gallons, you can get away with having 1 250w MH, but make sure it's high enough or it will cook/bleach all of your corals. How deep is your tank (water surface to sandbed)? The size of the bulb may only need to be 150w if you have a deep sand bed.

My fixture that I ordered is a MH + 4-6(?) at actinic lights. So I guess Im good, btw what is cooking and bleaching a coral?
 
that's not true about the actinic lighting. all of the bulbs we use are full spectrum and actinic supplement is not needed. the amount of actinic lighting people use over their tanks is far more than needed.
watts per gallon is a poor gauge to go by. it will depend on the distance from the bulb to the coral in question.
for a 34 gallon tank i agree that a 250 watt halide would be a good option.
i wouldn't use a 150 over a 34 gallon tank that housed high light corals, such as acropora.

I ordered a 380w (MH+ 2 actinic) light fixture, is that too much light?
 
no. it's definitely not too much light. do you have corals in the tank now? if so, make sure you acclimate them to the new light. if it's a lot brighter than your old fixture, there is a chance you can shock the corals with it. i would use some light diffusing material between the tank and bulbs for a few weeks. i like to use window screens...about 3 of them..and remove one a week until they are all gone.
 
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no. it's definitely not too much light. do you have corals in the tank now? if so, make sure you acclimate them to the new light. if it's a lot brighter than your old fixture, there is a chance you can shock the corals with it. i would use some light diffusing material between the tank and bulbs for a few weeks. i like to use window screens...about 3 of them..and remove one a week until they are all gone.

I do have coral (1), but it's new, it's actually use to have bright lights at my LFS. Thks. But is there any way that I could keep the fish from jumping out, because it's open top after I put in the MH fixture.
 
I do have coral (1), but it's new, it's actually use to have bright lights at my LFS. Thks. But is there any way that I could keep the fish from jumping out, because it's open top after I put in the MH fixture.

I'll be in the same situation as you. Doug said that a DIY screen made from a bridal veil would work best. With eggcrate you still have the possibility of them jumping through the holes.
 
exactly. check into your local crafts store. they should have rolls of bridal veil material. that seems to be the least light diffusing material reef keepers have found (that i've read thus far) that still allows an air exchange.
just make up a thin wooden frame that will fit the tank and staple or glue it to the frame.
 
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