Metal halide lighting

blakeoe · 07/13/2006, 11:55 AM

How much difference is it if you have two 200 watt lights or one 400 watt light? Im not planning on growing and really delicate corals just a few easy things. It's a 72 gallon bow front, about 23 high 50 long and 18 at the widest part.

Yinger · 07/13/2006, 12:04 PM

they don't make 200 metal halides... comes in 70, 150, 175, 250, 400 and 1000. It order to deteremine which one you want, you want to look at depth of your tank as well as length. In your case, you might want to take a look at 2x250s. you might be even able to get away with 2x175

blakeoe · 07/13/2006, 12:11 PM

The reason i ask is b/c a friend is selling one 400w light for very cheap. I have heard that i should use 2 250's but im just wondering how much of a difference it will make if i buy his 400watt (maybe down the road add a 150w) as opposed to the 2 250's. What are the benifits of having the light spread out? and is it worth the extra $200 for almost the same amount of wattage just spaced differently.

Yinger · 07/13/2006, 12:20 PM

with any lighting you can't calculate how much you need by watts per gallon. With halides you have to look at the intensity. With a 400 watt metal halide your going to need a large reflector and mount it really high so you won't burn your corals and also get the even distribution of light. your tank is too long to just have one bulb. And you don't want to mix and match wattage either due to the different intensity of each wattage. But if you have a closed top canopy and get 400 watts on your tank, that going to be overkill and you'll only have lighting on one side or in the middle depending on where you place it.

Yinger · 07/13/2006, 12:23 PM

the only reason why you would want to go 400 is your tank was over 24 inches deep, I've even heard as far as 30 inches deep. Otherwise you will have to mount the halides about a foot or more above the water level and that's going to cause a lot of wasted light.

mwood · 07/13/2006, 12:31 PM

You might get away with one 400w if you used a super sun reflector from sunlight supply. It casts a longer more narrow light pattern. You would mount it parallel to the tank between 12 to 18" off the water. I'd use a bluer bulb with that setup. No need for a 10k bulb over that tank.

07/13/2006, 11:55 AM	#1
blakeoe Registered Member Join Date: Mar 2006 Location: New Orleans Posts: 370	Metal halide lighting How much difference is it if you have two 200 watt lights or one 400 watt light? Im not planning on growing and really delicate corals just a few easy things. It's a 72 gallon bow front, about 23 high 50 long and 18 at the widest part. __________________ Somethings Fishy Around Here!! Current Tank Info: 72 gallon bow front

07/13/2006, 12:11 PM	#3
blakeoe Registered Member Join Date: Mar 2006 Location: New Orleans Posts: 370	The reason i ask is b/c a friend is selling one 400w light for very cheap. I have heard that i should use 2 250's but im just wondering how much of a difference it will make if i buy his 400watt (maybe down the road add a 150w) as opposed to the 2 250's. What are the benifits of having the light spread out? and is it worth the extra $200 for almost the same amount of wattage just spaced differently. __________________ Somethings Fishy Around Here!! Current Tank Info: 72 gallon bow front

07/13/2006, 12:04 PM	#2
Yinger Premium Member Join Date: Jul 2004 Location: Yorba Linda Posts: 3,657	they don't make 200 metal halides... comes in 70, 150, 175, 250, 400 and 1000. It order to deteremine which one you want, you want to look at depth of your tank as well as length. In your case, you might want to take a look at 2x250s. you might be even able to get away with 2x175

07/13/2006, 12:20 PM	#4
Yinger Premium Member Join Date: Jul 2004 Location: Yorba Linda Posts: 3,657	with any lighting you can't calculate how much you need by watts per gallon. With halides you have to look at the intensity. With a 400 watt metal halide your going to need a large reflector and mount it really high so you won't burn your corals and also get the even distribution of light. your tank is too long to just have one bulb. And you don't want to mix and match wattage either due to the different intensity of each wattage. But if you have a closed top canopy and get 400 watts on your tank, that going to be overkill and you'll only have lighting on one side or in the middle depending on where you place it.

07/13/2006, 12:23 PM	#5
Yinger Premium Member Join Date: Jul 2004 Location: Yorba Linda Posts: 3,657	the only reason why you would want to go 400 is your tank was over 24 inches deep, I've even heard as far as 30 inches deep. Otherwise you will have to mount the halides about a foot or more above the water level and that's going to cause a lot of wasted light.

07/13/2006, 12:31 PM	#6
mwood Premium Member Join Date: Jan 2004 Location: Winterset, IA 50273 Posts: 2,299	You might get away with one 400w if you used a super sun reflector from sunlight supply. It casts a longer more narrow light pattern. You would mount it parallel to the tank between 12 to 18" off the water. I'd use a bluer bulb with that setup. No need for a 10k bulb over that tank.