mh lighting confusion ,

toddmcgill · 04/26/2006, 11:58 AM

ok perhaps i am just dense so maybe someone can explain some things to me, i am setting up a 280, gallong display sps reef tank, total sys capacity of close to 500 gallons,the tank is 6ft x 30" x 30" so i am looking for lighting bright enough to propperly light 30" depth to keep sps top to bottom. i am planning on useing 1000w lights of some sort, but the more i research the more i get confused,i went to sanjays site, and of course no info on 1000w lights is available, so i start looking at 400w analysis just to get some idea which bulb ballast combos seem best,then i went and pulled up the 250watt charts to look and see how much brighter the 400 is than a 250, thinking it might be somewhat of a correlary to how much brighter a 1000w would be than a 400w,well his tests show a 10,000k 250w ushio having a higher ppfd than a 400w????
now in the past i have always used lux, but from what i understand ppfd is a better way, so is it possible that a 250w has more par than a 400 of the same k from the same company?? if so why would anyone use 400's just to spend more mney on elec.???

obviously i must be missing something. the more i study the more confused i become,in all other lighting i have ever studied there have been exponential increases in lux as wattages got higher, so that useing a single bulb always yeilded more par and lux than a pair of half wattage bulbs.now i seem to be finding that a higher wattage bulb has less par??? r am i misunderstanding ppfd.

anyhow if someone could give me a good idea how to get the best lighting for a 30" deep sps tank, that will provide optimum growth, color rendition and asthetics, i would be forever in your debt.

toddmcgill · 04/26/2006, 09:03 PM

i cant beleive noone has an opinion on this at all,i figured at least someone would be trying to talk me out of useing the 1000's.
is anyone else useing 1000's if so what have you found is the best bulb?? are 20,000 k 1000's as bright as 400w 10,000k?

Fast Fred · 04/26/2006, 09:36 PM

OK, I'll try...

Do you think that at 30" of depth that 400w x 3 fixtures will not be enough? I'd hate to foot the electric bill to run 1000w bulbs.

orlenz · 04/26/2006, 09:41 PM

some 250w bulbs will put out more par than some 400w bulbs, the ballast and reflector you use also play a big role in the output you will get, Personally I wouldnt use 1000w bulbs on any tank less than 36" deep. I would run (3) 400W 14k EVC bulbs on EVC Ballasts in Luminarc reflectors about 8" off the water. you will have plenty of light and a nice color also.

toddmcgill · 04/26/2006, 09:42 PM

i think that depends on what you call enough,i want the best growth and color i can get and electric bill is not a concern.i do think corals would survive and grow well under 400 w lights,but if they will do better under 1000's then thats what i want, what i cant understand is the huge discrepancies in the numbers from bulb to bulb and ballast to bulb,it amazes me that a 250 can outshine a 400 of the same k rating from the same company, which is what sanjays test's implicate, at least with some certain bulbs,i just wish i could somehow determine if that would be the case with the 1000w as compared to 400w bulbs, because while i dont mind the power bill i certainly cant justify spending more to get less,

toddmcgill · 04/26/2006, 09:51 PM

i guess to clarify my goals, what i want is to figure out what noon day sun readings are at a typical south pacific reef, and try to find a bulb that comes close tothe same par, while still having a nice blue tint that will make coral colors floresce.

toddmcgill · 04/26/2006, 10:09 PM

well here is a little something i copy and pasted from elsewhere.hope the original poster doesnt mind.

Sunlight is ca. 2000 um/m2/s. Not too many corals can tolerate light that bright without bleaching though. I'd shoot for a maximum of 500-700 as the very brightest light you'll want. For most corals you'll want closer to 300-400 as the max that they get. Corals that do best with lower lighting are probably better at <100.

Definitely get yourself something to measure light intensity, if only a cheap lux meter. In lux max. sunlight is ca. 100,000 lux. As such, really bright is about 30,000-50,000 lux. Moderately bright is ~10,000-20,000 lux, and moderate to dim would be nearer 5,000 lux and less.

Realize that it will vary seasonally too--brightest in summer, dimmest in winter.

looks like natural sunlight is around 100,000 lux, the average 10,000k 1000w bulb emits about 40,000 to 60,000 lux, however it does mention that most corals cant take this, which i dont understand since in nature they obviously do take this,even considering the uv absorption of water many acropora dominated reefs are very shallow and even exposed at mean low tides,so it seems to me that a 1000w light that produces roughly half of natural sunlight lux should be pretty safe.

any thoughts on this from anyone???

04/26/2006, 11:58 AM	#1
toddmcgill Registered Member Join Date: Mar 2006 Posts: 49	mh lighting confusion , ok perhaps i am just dense so maybe someone can explain some things to me, i am setting up a 280, gallong display sps reef tank, total sys capacity of close to 500 gallons,the tank is 6ft x 30" x 30" so i am looking for lighting bright enough to propperly light 30" depth to keep sps top to bottom. i am planning on useing 1000w lights of some sort, but the more i research the more i get confused,i went to sanjays site, and of course no info on 1000w lights is available, so i start looking at 400w analysis just to get some idea which bulb ballast combos seem best,then i went and pulled up the 250watt charts to look and see how much brighter the 400 is than a 250, thinking it might be somewhat of a correlary to how much brighter a 1000w would be than a 400w,well his tests show a 10,000k 250w ushio having a higher ppfd than a 400w???? now in the past i have always used lux, but from what i understand ppfd is a better way, so is it possible that a 250w has more par than a 400 of the same k from the same company?? if so why would anyone use 400's just to spend more mney on elec.??? obviously i must be missing something. the more i study the more confused i become,in all other lighting i have ever studied there have been exponential increases in lux as wattages got higher, so that useing a single bulb always yeilded more par and lux than a pair of half wattage bulbs.now i seem to be finding that a higher wattage bulb has less par??? r am i misunderstanding ppfd. anyhow if someone could give me a good idea how to get the best lighting for a 30" deep sps tank, that will provide optimum growth, color rendition and asthetics, i would be forever in your debt.

04/26/2006, 09:36 PM	#3
Fast Fred Registered Member Join Date: May 2004 Location: Northfield, NJ 08225 Posts: 1,170	OK, I'll try... Do you think that at 30" of depth that 400w x 3 fixtures will not be enough? I'd hate to foot the electric bill to run 1000w bulbs. __________________ Ya know, for a clown fish, you're not very funny! Member of the New Jersey Reefers Club Current Tank Info: 125g Reef Ready AGA /55g Top Fin Tank for a sump/refugium/ LifeReef Skimmer/ Changing over to SPS only

04/26/2006, 09:03 PM	#2
toddmcgill Registered Member Join Date: Mar 2006 Posts: 49	i cant beleive noone has an opinion on this at all,i figured at least someone would be trying to talk me out of useing the 1000's. is anyone else useing 1000's if so what have you found is the best bulb?? are 20,000 k 1000's as bright as 400w 10,000k?

04/26/2006, 09:41 PM	#4
orlenz Awaiting Email Confirmation Join Date: Feb 2005 Location: California Posts: 1,648	some 250w bulbs will put out more par than some 400w bulbs, the ballast and reflector you use also play a big role in the output you will get, Personally I wouldnt use 1000w bulbs on any tank less than 36" deep. I would run (3) 400W 14k EVC bulbs on EVC Ballasts in Luminarc reflectors about 8" off the water. you will have plenty of light and a nice color also.

04/26/2006, 09:42 PM	#5
toddmcgill Registered Member Join Date: Mar 2006 Posts: 49	i think that depends on what you call enough,i want the best growth and color i can get and electric bill is not a concern.i do think corals would survive and grow well under 400 w lights,but if they will do better under 1000's then thats what i want, what i cant understand is the huge discrepancies in the numbers from bulb to bulb and ballast to bulb,it amazes me that a 250 can outshine a 400 of the same k rating from the same company, which is what sanjays test's implicate, at least with some certain bulbs,i just wish i could somehow determine if that would be the case with the 1000w as compared to 400w bulbs, because while i dont mind the power bill i certainly cant justify spending more to get less,

04/26/2006, 09:51 PM	#6
toddmcgill Registered Member Join Date: Mar 2006 Posts: 49	i guess to clarify my goals, what i want is to figure out what noon day sun readings are at a typical south pacific reef, and try to find a bulb that comes close tothe same par, while still having a nice blue tint that will make coral colors floresce.

04/26/2006, 10:09 PM	#7
toddmcgill Registered Member Join Date: Mar 2006 Posts: 49	well here is a little something i copy and pasted from elsewhere.hope the original poster doesnt mind. Sunlight is ca. 2000 um/m2/s. Not too many corals can tolerate light that bright without bleaching though. I'd shoot for a maximum of 500-700 as the very brightest light you'll want. For most corals you'll want closer to 300-400 as the max that they get. Corals that do best with lower lighting are probably better at <100. Definitely get yourself something to measure light intensity, if only a cheap lux meter. In lux max. sunlight is ca. 100,000 lux. As such, really bright is about 30,000-50,000 lux. Moderately bright is ~10,000-20,000 lux, and moderate to dim would be nearer 5,000 lux and less. Realize that it will vary seasonally too--brightest in summer, dimmest in winter. looks like natural sunlight is around 100,000 lux, the average 10,000k 1000w bulb emits about 40,000 to 60,000 lux, however it does mention that most corals cant take this, which i dont understand since in nature they obviously do take this,even considering the uv absorption of water many acropora dominated reefs are very shallow and even exposed at mean low tides,so it seems to me that a 1000w light that produces roughly half of natural sunlight lux should be pretty safe. any thoughts on this from anyone???