T5 lights fact or fiction?

[MikeS]

well i have done some testing with the T5s. at 20" below the water line MH and T5s have about the same par reading..

How many watts of T5 versus watts of MH? This is critical to the big picture...

you can not go by watts. you must look at the lumen per watt to get the intensity. lets see if i can remember..

Yeah, watts are not necessarily a good indicator of intensity, as they relate to power consumption....

Watts per lumen...hmmm....this would be a more accurate description of bulb efficiency, not necessarily intensity. Many other factors come into play, like total lumens, surface area of bulb, ect....On top of that, lumens only relate to intensity in the visible spectrum, it does not account for total output of the bulb.

Really, for reefkeeping, the best indicator of bulb intensity is the PAR rating.

vho=35 lumens per watt
pc=45lumens per watt "vho and pc might be mixed up."
T5=75lumen per watt
MH=85lumens per watt...

Hmmm...where did you get these numbers? A quick "google" turned up these numbers for me... A 110 watt VHO is usually around 7000 initial lumens, or 64 watts per lumen. A 96 watt PC is around 8800 lumens, or 92 lumens per watt. A 54 watt T5 produces around 5000 lumens, about 93 lumens per watt. A 400 watt MH produces around 40000 lumens, 100 lumens per watt. So...T5, PC and MH are all in the 90-100 lumen per watt range. Still, this only indicates the efficiency of the the bulb, not the intensity. The MH beats them all in PAR vs depth, due mainly to the high lumen output based on the actual bulb surface area producing the light. It will take 8 T5's to produce the same amount of lumens as a single 400 watt MH, but the MH will still have a smaller dropoff of PAR based on tank depth, because of the much larger bulb surface area required by the T5 to generate the same amount of lumens.

just to dispell the myth that T5s are just small pc's. so if you can get the same wattage of T5 to fit you can keep the same things under it...

From a total lumen output standpoint, sure, T5's are pretty close to PC's...but Id like to see a PAR vs. depth comparison between the two...I belive the PC bulb has a smaller surface area than the T5, therefore I think the PAR of the PC will not drop off as quite as quickly as the T5...I could be mistaken on the surface area comparison however...

however same light within the whole tank. remember light is aborbed no matter what direction is goes.

Light is not "absorbed" by water. It is refracted and reflected by water. Some goes out the sides of the tank, some is reflected at the surface, ect. The deeper you go, the greater the degree of refraction. Longer wavelengths of light have a greater delta of deflection, and are diffused by water more quickly than others, allowing less of them to penetrate deeply into the tank.

MH just focus on one spot and thus the lighting is not absorb in that spot allowing it to refract deeper at that focused area. if nothing is in the water colum to absorb the light any lighting will countinue to travel until it is fully absorbed.

:?: Lost me on that one...the water itself is what is refracting the light. No absorbtion of light by water whatsoever is taking place. The light is diffusing and being refracted/reflected, long wavelenghts first (this is why things appear more "blue" the deeper you go in water...the shorter wavelength of blue light diffuses out more slowly than the red or green wavelenghts) Particulate matter in the water column may however "block" out some light, allowing less of it as a total to reach the lower depths.

once the light hits the bottm sand it reflects back and refracts again=greater light intensity at the bottom.

Greater light intensity at the bottom compared to what? It doesn't work that way...the amount of light being reflected back into the water column from your substrate will never equal the amount of light striking it in the first place, because of refraction in that new direction as well.

basically flourescents provide a greater surface area to allow for greater absorbtion of light. intensity wise T5's are about the same as MH.

Yes, the greater surface area of the fluorescent bulb (compared to a Metal Halide) means the light produced is more quickly refracted by the water. That means less of it makes it to the bottom of the tank, and ends up somewhere else. T5's may have a comparable watt/lumen output to a MH, but they simply don't have the PAR to water depth ratio of a MH, which realistically is the best measure of bulb "intensity"

MikeS

 

[prow]

How many watts of T5 versus watts of MH? This is critical to the big picture...

ok here you go here
Penetron 41 HO watts 54, lumens 5000, and PAR 69.5 uE/s
Halide 250 watts 23000 lumens PAR 310 uE/s

so:
T5} 54 x 5 =270 watts, 5 x PAR 69.5 =347uE/s, and 5 x 5000 =25000lumen
MH} 250 x 1 =250 watts, = 1 x PAR 310 uE/s, and 1 x 23000 =23000lumen
close huh.
however i did actual testing not number adding so whatever the arguement is i tested it and they are pretty much the same at 20" below the water line as far as the par goes. one the setup i have now is 8-80watt T5's thats 640watts. if i used MH 2-250watt bulbs thats 500watts.(tank is 5 feet) get more light in this set up with the T5's.

Really, for reefkeeping, the best indicator of bulb intensity is the PAR rating.

yup thats what our corals like.

It will take 8 T5's to produce the same amount of lumens as a single 400 watt MH, but the MH will still have a smaller dropoff of PAR based on tank depth, because of the much larger bulb surface area required by the T5 to generate the same amount of lumens.

nope check here for your 400watt MH vs T5 http://www.pacdist.com/HO T5 Vs HID_files/frame.htm but 250w MH out do 400w MH so i compared the 250watt MH when i did my test.

Light is not "absorbed" by water. It is refracted and reflected by water. Some goes out the sides of the tank, some is reflected at the surface, ect. The deeper you go, the greater the degree of refraction. Longer wavelengths of light have a greater delta of deflection, and are diffused by water more quickly than others, allowing less of them to penetrate deeply into the tank.

never said it was, in fact i said the main thing was what is in the water. i even said if nothing was in the water the light would countinue until something absorbed it..

:?: Lost me on that one...the water itself is what is refracting the light. No absorbtion of light by water whatsoever is taking place. The light is diffusing and being refracted/reflected, long wavelenghts first (this is why things appear more "blue" the deeper you go in water...the shorter wavelength of blue light diffuses out more slowly than the red or green wavelenghts) Particulate matter in the water column may however "block" out some light, allowing less of it as a total to reach the lower depths.

???? never said that either. the pin point MH foucus on one spot= more light in that spot so it penetrates more in that spot. flouescents hite the water surface evenly=more of the light absorbed at a more shallow deapth. do not want to try to explain. sorry.however FYI i do know my physics here is a thread i talk about reflect refract stuff. i give a few links there as well. read thourgh it them comeback you will know what i am talking about. here is the link to that thread http://www.reefcentral.com/forums/showthread.php?s=&threadid=620844 o yeah my name there is hlama.

Greater light intensity at the bottom compared to what? It doesn't work that way...the amount of light being reflected back into the water column from your substrate will never equal the amount of light striking it in the first place, because of refraction in that new direction as well.

greater MH vs flouescent read the thread i gave for the reflect refract.

Yes, the greater surface area of the fluorescent bulb (compared to a Metal Halide) means the light produced is more quickly refracted by the water. That means less of it makes it to the bottom of the tank, and ends up somewhere else. T5's may have a comparable watt/lumen output to a MH, but they simply don't have the PAR to water depth ratio of a MH, which realistically is the best measure of bulb "intensity"

at 20" yeah they do. like i said i tested myself. you should too. see for your self. i believe maybe at 30" below the water the par will fade with the T5s. but my tank is only 24"hight with a sand bed of 4" so i could not test below 20". cant say anything about the par below 20". but yes less of the light from the T5's make it to the bottom, thats what i said. but still at 20" below enough of the T5 light penetrates to equal the MH, or at least is so close doesnt make a differance as far as the PAR level goes.

 

[MikeS]

ok here you go here
Penetron 41 HO watts 54, lumens 5000, and PAR 69.5 uE/s
Halide 250 watts 23000 lumens PAR 310 uE/s

so:
T5} 54 x 5 =270 watts, 5 x PAR 69.5 =347uE/s, and 5 x 5000 =25000lumen
MH} 250 x 1 =250 watts, = 1 x PAR 310 uE/s, and 1 x 23000 =23000lumen
close huh..

Ok...good, we are talking about a similar amount of lumens and watts consumed here....

however i did actual testing not number adding so whatever the arguement is i tested it and they are pretty much the same at 20" below the water line as far as the par goes. one the setup i have now is 8-80watt T5's thats 640watts. if i used MH 2-250watt bulbs thats 500watts.(tank is 5 feet) get more light in this set up with the T5's...

I don't doubt for a minute that you were seeing similar PAR ratings...I have seen plenty of PAR comparisons on MH vs PC where the numbers were similar in shallow tanks, I suspect the T5's have similar intensity to PC's....

It will take 8 T5's to produce the same amount of lumens as a single 400 watt MH, but the MH will still have a smaller dropoff of PAR based on tank depth, because of the much larger bulb surface area required by the T5 to generate the same amount of lumens.

nope check here for your 400watt MH vs T5 http://www.pacdist.com/HO T5 Vs HID_files/frame.htm but 250w MH out do 400w MH so i compared the 250watt MH when i did my test.

hmmm...perhaps you misunderstood what I was saying. I read this link, it talks about lumen output dropoff over the life of the bulb. Also, it was in reference to their use in large open spaces, like hangers, it had no data concerning use on reef tanks. I was refering to PAR dropoff versus DEPTH of the tank. On the lumen dropoff...according to your link, the overall lumen output of the MH bulb vs a similar wattage T5 setup converge around 10,000 hours bulb useage. Given a 12 hour a day photoperiod, the MH puts out more total lumens than the T5 setup for well over a year. Most reefkeepers replace their bulbs yearly anyway...(I'd like to talk about spectral shift over time also, I'll do it later in the post...)
The point I was trying to make was that the PAR dropoff (given equal lumen outputs of course) of a T5 (or any flourescent bulb for that matter) versus a MH given an increase in depth of the tank will be greater. Flourescents simply lack the water penetrating characteristics of a MH due to the surface area of the bulb producing the light.

Light is not "absorbed" by water.

never said it was, in fact i said the main thing was what is in the water. i even said if nothing was in the water the light would countinue until something absorbed it..

my apologies, I must have misinturpreted your statement....sorry...it's all good...

the pin point MH foucus on one spot= more light in that spot so it penetrates more in that spot. flouescents hite the water surface evenly=more of the light absorbed at a more shallow deapth. do not want to try to explain. sorry.however FYI i do know my physics

As do I... No need to apologize, I understand exactly what you are saying. In a nutshell, you are saying that MH gets a higher actual PAR to the bottom of the tank because of the point intensity, but this PAR is limited to a smaller total surface of the bottom of the tank because of the exact same thing, where a flourescent bulb may get a lower actual PAR, but the total overall PAR is spread over a much larger surface of the bottom of the tank...(see attached drawings)...

Greater light intensity at the bottom compared to what? It doesn't work that way...the amount of light being reflected back into the water column from your substrate will never equal the amount of light striking it in the first place, because of refraction in that new direction as well.

greater MH vs flouescent read the thread i gave for the reflect refract.

Ok, again I must have misinturpreted your post. I agree...the flourescent light will have a greater spread of overall PAR reaching the bottom of the tank, due to the large surface area of the bulb

at 20" yeah they do. like i said i tested myself. you should too. see for your self. i believe maybe at 30" below the water the par will fade with the T5s. but my tank is only 24"hight with a sand bed of 4" so i could not test below 20". cant say anything about the par below 20". but yes less of the light from the T5's make it to the bottom, thats what i said. but still at 20" below enough of the T5 light penetrates to equal the MH, or at least is so close doesnt make a differance as far as the PAR level goes.

Are the PAR values absolutely equal for an equal amount of lumen output of MH vs T5 in your tests? Or are they simply close? It may seem like a small point to bicker over, but it does lend to the overall verdict. I don't doubt at all that you observed PAR ratings comparible to the MH in a shallow tank. But all that you can difinatively say from this is that T5's will provide similar PAR in a shallow tank. Lots of other things come into play here, like tank depth, overall PAR required, ect...PC's will do the same, yet they are generally disreguarded as an unsuitable primary light source for higher light corals.

Don't get me wrong here, I'm neither bashing T5's nor you, prow, I just am trying to cover some bases. T5's are reletively new to us here in the US, I just want to see some more good info in them before I'm ready to accept them as a legitimate replacement for MH when dealing with high light corals like SPS, also, aside from heat production, I'd like to see what specific advantages T5's have over MH's that would justify their use in a high light demanding situation...

Most claims I have seen state T5's last 18-24 months. From a total lumen output I can buy this...but what about spectral shif in the bulb? Most reefkeepers I know replace bulbs not becuse of lumen output, but because of the shifting spectrum. Is there any evidence out there that suggests T5's maintain theor spectral integity any longer than other bulbs? If not, than the low Lumen dropoff arguement for T5's loses its teeth, as the bulb will need to be replaced on a comparible schedule anyway...

MikeS

 

[prow]

I don't doubt for a minute that you were seeing similar PAR ratings...I have seen plenty of PAR comparisons on MH vs PC where the numbers were similar in shallow tanks, I suspect the T5's have similar intensity to PC's....

the thing about the pc's is a,for example, a 36watt pc is about the same in everyway when compared to a 18watt T5. these are the only pc and T5 test i ran. this was my sump lighting. i switched from pc to T5 after. look wise the 18watt T5 is brighter than the 36watt pc. the pcs loss half the par at 9" below the water surface T5 start to loss the par at 18" i believe the MH dont start to loos much untill 24"(didnt test this but have read about it many times).

The point I was trying to make was that the PAR dropoff (given equal lumen outputs of course) of a T5 (or any flourescent bulb for that matter) versus a MH given an increase in depth of the tank will be greater. Flourescents simply lack the water penetrating characteristics of a MH due to the surface area of the bulb producing the light

.
totally agree. pc's however dont even come close to T5's. its the reflector and bulb size. make kinda pin point, more so than the pc's anyway.

my apologies, I must have misinturpreted your statement....sorry...it's all good...

yeah i read through the thread again i think we were saying the samething in a different way.

As do I... No need to apologize, I understand exactly what you are saying. In a nutshell, you are saying that MH gets a higher actual PAR to the bottom of the tank because of the point intensity, but this PAR is limited to a smaller total surface of the bottom of the tank because of the exact same thing, where a flourescent bulb may get a lower actual PAR, but the total overall PAR is spread over a much larger surface of the bottom of the tank...(see attached drawings)...

yup exactly.

Ok, again I must have misinturpreted your post. I agree...the flourescent light will have a greater spread of overall PAR reaching the bottom of the tank, due to the large surface area of the bulb

yup again,

Are the PAR values absolutely equal for an equal amount of lumen output of MH vs T5 in your tests? Or are they simply close? It may seem like a small point to bicker over, but it does lend to the overall verdict. I don't doubt at all that you observed PAR ratings comparible to the MH in a shallow tank. But all that you can difinatively say from this is that T5's will provide similar PAR in a shallow tank. Lots of other things come into play here, like tank depth, overall PAR required, ect...PC's will do the same, yet they are generally disreguarded as an unsuitable primary light source for higher light corals.

ahh what the difference is here is light intensity vs irradiance. the rate of photosynthesis will depend upon irradiance, the amount of light striking the coral, rather than light intensity, the brightness of the bulb. A 60 Watt light placed very close to a coral would provide more light for photosynthesis than a 100 watt bulb located much further away.irradiance also encompasses units of area (square meter, m2) and time (min), thus giving the amount of light energy striking a 2-dimensional surface over a period of time. The most common units of light irradiance are "uEinstein /m2 /min." An "Einstein" is equivalent to 1 mole of photons, the fundamental unit of light.

Don't get me wrong here, I'm neither bashing T5's nor you, prow, I just am trying to cover some bases. T5's are reletively new to us here in the US, I just want to see some more good info in them before I'm ready to accept them as a legitimate replacement for MH when dealing with high light corals like SPS, also, aside from heat production, I'd like to see what specific advantages T5's have over MH's that would justify their use in a high light demanding situation.

i understand i went through the same thing. FYI i see some "moderators" in forums that said no way now i see them saying for a 24" tank T5 is the way to go. anything deeper go fo the MH. total flip flop from when i first started to look into these.

Most claims I have seen state T5's last 18-24 months. From a total lumen output I can buy this...but what about spectral shif in the bulb? Most reefkeepers I know replace bulbs not becuse of lumen output, but because of the shifting spectrum. Is there any evidence out there that suggests T5's maintain theor spectral integity any longer than other bulbs? If not, than the low Lumen dropoff arguement for T5's loses its teeth, as the bulb will need to be replaced on a comparible schedule anyway...

not sure how long the spectrum lasts have heard it was 18 months before they started to loss their spectrum.
as far benifits heat the biggest no need for chillers or extra fans. close to $1000 savings here. you can hold a T5 in your hand while it is going and not get burnned.(less water evaporation) bulb replacement is about $100 a year for 1 MH. for 5 T5s its about the same(if you replace the T5's every year.) so small saving here if not overdriven, because can replace every 18-24mo. but for sps you need to over drive the T5's=replace every year. for me i like the T5 look better than the MH, you still get gliter lines just doesnt go as deep. here are a few links for some more info.
http://translate.google.com/transla...Flanguage_tools
http://translate.google.com/transla...Flanguage_tools
for me if your tank is more than24" deep Mh is the way to go. any tank that is not any deeper the T5 is a good alterative to MH. here is something i think you should look at. read what he says about the T5's, (i like my tank more white more aqua blue and less blue plus, i just it more white than his setup) this a tank of the month feb 2005 fan with only T5's.
http://reefkeeping.com/issues/2005-03/totm/index.htm

 

[prow]

o and you can play with different lights an very the look and spectrum. MH not to much to choose from. plus no start up delay(just a little bounus)

 

[prow]

this is what he had to say about his T5 setup:
Lighting:

After getting good results with T5 bulbs in my previous 30-gallon system, they were the natural choice for my current 110-gallon setup. While the 24-watt T5s did a decent job maintaining SPS color at shallower depths, I was pleasantly surprised to discover that the 54-watt versions allowed me to maintain SPS even on the sandbed.

Top view of the T5 reflectors.
I started out with six 54-watt T5s, but it wasn't long before I increased the lighting to eight 54-watt T5s with the addition of more light demanding corals. The bulb combination now consists of five ATI Aquablue Special (11,000K) and three ATI Blue Plus (Radium equivalent) for maximum intensity and yet still provides a balanced spectrum for coral growth and color.

After using T5 bulbs for over two years, and almost nine months in my current tank, I must say that I am very pleased with the results in terms of coral growth and color. Aside from quality T5 tubes, equally important are the mirror finish ATI parabolic reflectors that rest directly on the tubes for maximum reflectivity. One of the keys to getting good results with T5 bulbs, I believe, is to keep your SPS no more than 18" from the light source. For intensely colored SPS (i.e. reds, blues, pinks, neon yellows), I keep them less than 10" away. The T5 bulbs are no more than three inches from the water surface. Three 24-watt T5 bulbs light up the refugium and another six 24-watt T5 bulbs cover the propagation tank.


one more thing about the cost. if you get MH you have to factor in the cost of supplement lighting, because dont need any with the T5's.

 

[prow]

lol i keep thinking of more stuff. the other thing is we have (i) have been talking about the 54watt bulbs, but they now have 80watt T5 bulbs. i am geussing these will penetrate even more than the 54watters. i actually just ordered the T5 80watters from fishgeeks. last week. going to have test these when i get them setup.

 

[plack]

Allot of the heat from lights can be taken away with fans and also placing a fan atop the tank cools the entire tank down yes more evaporation occurs but unless your house is above 80ºF fans should be able to keep it at a reasonable level.

As far as different lighting goes MH has primarily 10K/12K/14K/15K/20K and of course different brands have different spectrum peaks in any kind of light mh/vho/pc/t-5 and no supplementary light is required for mh and if you use say a 14K bulb if looks nicer to many. Also my little experience with a single t-5 was that it went bad in 6-7 months just got really dim. Also 6-8 t-5 bulbs seem to cost more than or equal to a mh not cheaper. I have seen articles about lights lasting years(icecap-vho)(also some guest speakers I have heard talked about mh lasting 3 years with only a small portion of it off) and still mostly in the good spectrum I believe that is due to the ballast. and pc's well some are allot more than others I see them $22-46 at stores for each 65 watt and online $18-25 plus shipping add a couple of those up and thats not cheaper than say one reefmax or xm $50 250 watt mh bulb. So what ever your preference you can do it just remember mh penetrates deeper but narrower great for depths pc/vho/t-5 all are more even but won't penetrate as deep

 

[MikeS]

Yeah, pretty much everybody I have spoken to that has T5's is very pleased with them...In fact I've been considering them for my 20gal Long when I get it set up as a nano...I won't do SPS in that tank however due to the very shallow nature of the tank, I think SPS would quickly outgrow it...I'm also considering replacing the PC's in my VHO/PC combo with T5's, but I'll likely hold off on that until they become a bit more mainstream and hopefully the price comes down on them a bit.

On the spectral shift...I'm sure ballasts, ect. comes into play here, but 18 months seems like a long time to go before seeing a significant shift...(btw the first 2 links you gave didn't work for me ) What would differ in the T5 from other bulbs that would allow it to maintain its spectrum? The shift in spectrum is due to the phosphors degrading, won't this occur at the same rate in a T5 as in any other flourescent bulb?

Yeah, I've seen that totm before, nice looking tank...it looks like he has had his corals under the T5's for just over a year now...

MikeS

 

[prow]

Allot of the heat from lights can be taken away with fans and also placing a fan atop the tank cools the entire tank down yes more evaporation occurs but unless your house is above 80ºF fans should be able to keep it at a reasonable level.

i live in so cal. the tank i am setting up now is 150gal setup and with just 2 T12 40watt bulbs (just growing coraline for now) the tank temp is 80 and this is with 4-4"fans. the T5's will be much cooler than the T12's. halides i would no dout have to buy a chiller. for lets say $1000ish plus the supplement light would be for my tank 2 96watt pcs=about $200 or more. have too add this to startup cost. $1200 extra. if you live in a cooler area might not be an issue.
for me big issue.

 

[prow]

mikes,
i will try to give those links again. my thinking is they dont burn the phos. as fast because it uses less wattage per lumen than pc's or VHO's. its just more efficient. ok try these:
http://translate.google.com/transla...&hl=en&ie=UTF-8&oe=UTF-8&prev=/language_tools
and this one
http://translate.google.com/transla...&hl=en&ie=UTF-8&oe=UTF-8&prev=/language_tools

 

[prow]

yeah they worked

 

[prow]

ooppss for the fist page on those this the first page http://translate.google.com/transla...&hl=en&ie=UTF-8&oe=UTF-8&prev=/language_tools

 

[MikeS]

got em that time...I love German to English translations... :lol:

MikeS

 

[plack]

so prow you say the lights are 3" above your tank cant you fit a fan on the side of the tank/canopy to blow across the top of the tank underneath the lights ? I do this with my 440watts of vho just 3" or less above my 55 gallon and when its 78 ºoutside my tank kepps real close to that but i know in california it gets above 78º having lived there for decades (simi valley/Chatsworth area) and lot's of peopl had an airconditioner for use when it got extremely hot a 10,000 btu 1 room unit is only say under $200. wich is way cheaper than a cooler for your tank and you get to enjoy it as well

 

[fleetbox]

80 watt T5's! Would it make any differance in a tank that is 22" deep? How many of these would you sugg for 60"X18X22? Will T5's overpower LPS, softies?

 

[MikeS]

the 80 watt bulbs are 72" long, I believe....

MikeS

 

[prow]

so prow you say the lights are 3" above your tank cant you fit a fan on the side of the tank/canopy to blow across the top of the tank underneath the lights ? I do this with my 440watts of vho just 3" or less above my 55 gallon and when its 78 ºoutside my tank kepps real close to that but i know in california it gets above 78º having lived there for decades (simi valley/Chatsworth area) and lot's of peopl had an airconditioner for use when it got extremely hot a 10,000 btu 1 room unit is only say under $200. wich is way cheaper than a cooler for your tank and you get to enjoy it as well

i did exaclty that. about a month ago this is a hot summer here its been 85-90+ all last week couple. passed 2 days much better but now we have thunderstorms popping up all over. and september is the hottest month. i think its been 100+ in the valley. i have four 4" fans in there right now with a 10,000 btu window airconditioner. but still keeps at 80 with the T12's and ac on. was peaking at 85+ before i got the ac. its humid here too, that doesnt help. its great for my nano but for the 150gal my pumps and powerheads produce some good heat. and my tank is acrylic doesnt disipate heat as well as a glass tank. MH i would need a chiller. 80 is cool its steady only drops to 79 at night. the T5's will run cooler so no worries. i will need my heater for winter though. good looking out though thanks. the other thing at least with this tank is, it has a crack on the top. its repaired and small but dont want it to recrack. MH can heat up the top acrylic no matter what you do, well unless you put them 24" high.

 

[prow]

80 watt T5's! Would it make any differance in a tank that is 22" deep?

any difference with what? 54watt T5's yeah.

How many of these would you sugg for 60"X18X22?

the 80watts are 60" thats almost my tank but mine is 72" long. i ordered 6-80watt. i mixed the bulbs different than the TOTM, i dont really like his lighting to blue for me. i went with the 1sun 6000k ATI, 4 aquablue 11K and 1 atinic/blue plus. running with 2 660 icecap ballast. here is a link to the ones i ordered. they have a lot of good products.IMO mine.http://www.reefgeek.com/products/categories/lighting/104073.html

Will T5's overpower LPS, softies?

well it depends on the coral, bet you heard that one a few times. hehe i hate when people say that. for the most part na, most will be happy. MH are "stronger", for lack of a better word, than T5's example; any coral directly under a MH is getting blasted by it, T5's dont do this.(this is good and bad depending on the coral) -there is that dam saying again. one thing if your going with lps and softies dont need to overdrive them just use the regular ballast for them.
and mikeS yeah those stupid dumb translator dumb stupid things. :badgrin:

 

[plack]

good luck prow I would still do sompthing to get it down a little lower at night if I could like maybe a fan on the sump as well and/or lift the light canopy up with pulleys from the ceiling at night to get more direct fan usage (this is how mine is ) I remember living in an apartment having an airconditioner on all the time going in and out it was like thermal shock 100º to 73º and back again I don't miss that but miss the sunny winters Paul