AJtheReefer
New member
maxrep,
What distance are you keeping the fixture from the tank and from the water? What lamps are you using?
What distance are you keeping the fixture from the tank and from the water? What lamps are you using?
T-5 Ignorance
- Thread starter maxrep12
- Start date
In my mind, the most important component of a spot light is the shape and design of the reflector housing that serves to focus the light. A MH bulb without a reflector is going to cast light in all directions. A MH bulb fitted with a reef reflector is designed to light a 2x2 square rather than serve as a spotlight. Both T-5 and MH bulbs are used with specific reflectors designed to light square footage of the floor beneath them. A MH bulb will cover a 2x2 square, a 48inch T-5 may cover 4ft x 1ft. Different coverage patterns, but the same goal. I can see a bit more of a spotlight effect under MH in the center of its coverage square - but thats about it, a bit more.
Before purchasing my lights I talked with several retailers. Many even suggested that I use 4 x 400 watt halides plus some actinic. So whether I used 250w MH or 400w MH I was looking at 1200watts to 1800watts(200w for actinic) to light this tank.
Before purchasing my lights I talked with several retailers. Many even suggested that I use 4 x 400 watt halides plus some actinic. So whether I used 250w MH or 400w MH I was looking at 1200watts to 1800watts(200w for actinic) to light this tank.
The Grim Reefer
Ready for some NOBALL!!!
maxrep12 said:
You think a single T5 would put out the same intensity as a 250 watt Halide? Wont happen. Again you are talking about spreading the light to be focused by the reflector out along nearly four feet of lamp driven by only 54 watts as opposed to 250 watts in six inches with the halide.
There have been a couple of people on the board measuring PAR on T5's and they are supposed to be about equal to 175 watt halides which aint bad for fluorescents. The Aquablue lamp puts out the most PAR, go figure. I thought it would have been the suns.
Don't get me wrong, I like the T5's. I'm just realistic about their capabilities.
The Grim Reefer said:
We have to compare apples to apples here, or watts to watts. Of course a 250w MH is going to have more intensity than a 54watt T-5. You are supposed to overlap that 1x4 coverage area of the T-5 bulb using multiple bulbs. The only way to compare output is to examine several areas of the sand bed in a tank for PAR after the lights have been installed to give proper coverage.
I am interested in finding out if there are indeed any "sand bed" light intensity issues between these lighting systems with all factors considered from equal coverage to equal watts.
The Grim Reefer
Ready for some NOBALL!!!
Let us leave it here, Halides maintain their original intensity deeper into the water than Fluorescents. That doesn't mean you can't grow clams on the sand with T5's, just that higher light demanding critters placed on the sand will likely do better to some extent with halides. It all really depends on how things are set up and how tall of a tank you have. From my experience I can tell you that in a 24" tall tank Montipora frags will not grow as quickly in the sand as they do halfway up the rocks.
Herbert T. Kornfeld
In Memoriam
So a water flow comparison is like what you are saying Grim? If you have 1000gph going into a tank with a pipe facing straight down you will get much more flow to the bottom because of its single outlet (like halides point source) vs. if you used a spraybar (T-5) with 100 holes across the top? Both provide 1000gph to the tank, but the single port/point will provide more intensity at the bottom?
I started another thread where I was hoping to get some more input w/o crashing this thread:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=482362
maxrep12, and anyone else who has more info on T-5s please respond.
I started another thread where I was hoping to get some more input w/o crashing this thread:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=482362
maxrep12, and anyone else who has more info on T-5s please respond.
The Grim Reefer
Ready for some NOBALL!!!
In a weird sort of way, Yes.
Hi Maxrep12, nice tank!
Wouldnââ"šÂ¬Ã¢"žÂ¢t the right way to make the comparison between lighting systems be based on lumen output instead of watts?
400w metal halide bulbs will produce 41000 lumens (102.5lumens/watt) when new and usually have a mean lumen output somewhere in the 30000 lumens range after use (75l/w). 250w MH will produce 21000 initially and 16,000 mean (64l/w).
When run at 54w, a 48" t5 will produce 5000 lumens. That makes the T5 run at 92.6 lumens per watt. Overdriving the bulbs at 80w should produce 7400 lumens per bulb (assuming the same efficiency). T5s are supposed to maintain the same high level of lumen output over a longer time than metal halides.
As long as both bulbs use similarly efficient reflectors a comparison could be made based on total lumen output. For example 16 T5s (16x5000) would produce 80,000 lumens which is similar to the output of 2x400w or 4x250w metal halides with new bulbs. If the same 16 T5s are overdriven to 80w/tube they would crank out 118,400 lumens or approximately 3x400w or 6x250w MH.
I realize that halides are more of a point source of light and the light output from a fluorescent tube is not. Or is the argument really that the photons from a metal halide are more intense than those from a fluorescent tube?
Is the amount of light at the bottom of the tank a misperception because fluorescent tubes have better light distribution?
I have been researching this because I am setting up a 150g -30" deep tank and want to use t5s for the lighting or use them to supplement 250w or 400w halides.
Wouldnââ"šÂ¬Ã¢"žÂ¢t the right way to make the comparison between lighting systems be based on lumen output instead of watts?
400w metal halide bulbs will produce 41000 lumens (102.5lumens/watt) when new and usually have a mean lumen output somewhere in the 30000 lumens range after use (75l/w). 250w MH will produce 21000 initially and 16,000 mean (64l/w).
When run at 54w, a 48" t5 will produce 5000 lumens. That makes the T5 run at 92.6 lumens per watt. Overdriving the bulbs at 80w should produce 7400 lumens per bulb (assuming the same efficiency). T5s are supposed to maintain the same high level of lumen output over a longer time than metal halides.
As long as both bulbs use similarly efficient reflectors a comparison could be made based on total lumen output. For example 16 T5s (16x5000) would produce 80,000 lumens which is similar to the output of 2x400w or 4x250w metal halides with new bulbs. If the same 16 T5s are overdriven to 80w/tube they would crank out 118,400 lumens or approximately 3x400w or 6x250w MH.
I realize that halides are more of a point source of light and the light output from a fluorescent tube is not. Or is the argument really that the photons from a metal halide are more intense than those from a fluorescent tube?
Is the amount of light at the bottom of the tank a misperception because fluorescent tubes have better light distribution?
I have been researching this because I am setting up a 150g -30" deep tank and want to use t5s for the lighting or use them to supplement 250w or 400w halides.
Roadtoad, thanks for the numbers.
This is a hard comparison simply because there are many factors. Lumens are indeed a great way to compare actual light output. The other side of the coin to be looked at in that scenario is the differing lumen outputs of MH or T-5 bulbs based on Kelvin ratings. I think the Auquablue+ T-5 has the greatest PAR. I also know from experience that a 20k MH bulb and a 5500k MH Differ a good bit in actual lumen output.
Another good observation you made was light distribution. T-5's will cover more evenly but will lack the glitter lines of MH bulbs.
This is a hard comparison simply because there are many factors. Lumens are indeed a great way to compare actual light output. The other side of the coin to be looked at in that scenario is the differing lumen outputs of MH or T-5 bulbs based on Kelvin ratings. I think the Auquablue+ T-5 has the greatest PAR. I also know from experience that a 20k MH bulb and a 5500k MH Differ a good bit in actual lumen output.
Another good observation you made was light distribution. T-5's will cover more evenly but will lack the glitter lines of MH bulbs.
Herbert T. Kornfeld
In Memoriam
Home Depot is undergoing a multimillion dollar renovation of their lighting. They are replacing their high-bay 400watt halides (average 5 per narrow aisle, more in wider ones as need be) with HO T-5 lighting. One fixture consists of 6 54watt bulbs, and they are putting 6 fixtures in each similar aisle. I tell ya, they have been had. The managers are all convinced that the new fixtures are going to be soo much brighter and cost less to operate. The installers offered me as many of the old high-bay fixtures and bulbs as I wanted...but the ballasts are all 480v.
My take: Yes, the aisles are brighter, but not by much really, and the reason isnt the bulbs so much. I used a photo meter and found a slight increase in lumens. One manager responded by claiming that the new lights were more natural looking...yeah, right. They are obviously beauty lights...very blue-red>>purple. All the orange in the store really stands out now as it fluoresces. So the perception is that things are brighter. I told the manager that if they instead invested in electronic halide ballasts and higher K bulbs (6500K instead of the 3000-4000K bulbs they use now that do give off a good, but slightly yellow-green look) they could have saved themselves some loot and it would look even better. Wattage-wise, there is very little change. At 54 watts per bulb, 6 per fixture, and 6 per aisle, thats 1944 watts in an aisle that once had 2000 watts of halide....oh my, a whole 66 watts less. But it does look brighter considering the wattage...
But thats because the new fixtures have actual polished reflectors, where the old halide high-bays had nothing but plexi bell-sheilds around them that didnt focus any light downwards. Im sure if some decent bell-reflectors would have been used on the old halides...and some higher K bulbs, the results would have been even that much more impressive than the new retrofit. Im sure HD has lots of money to waste on replacing lighting fixtures and has to spend it or pay it in taxes anyways...so why not. Of course, they could pay their employees more and spend it that way, but no, they are wasting it on a new lighting system that will result in more wasted money for an inferior product. On top of that, the ballasts are a HD patent with Cooper Lighting, due to the 480v rails they need to work in. The ballasts are blowing. About one in eight needs 'tweaking, so as of right now, 1/8 the bulbs in the store are blown. Great technology. On the upside, the T-5s might not make as much heat as the halides, so maybe the store will be cooler in the summer, but other than that, this venture by HD has been very informative about the benefits of T-5 vs. halides. Im sure that they make good actinics, and offer an intensity better than PC bulbs, but Im not sold any more.
My take: Yes, the aisles are brighter, but not by much really, and the reason isnt the bulbs so much. I used a photo meter and found a slight increase in lumens. One manager responded by claiming that the new lights were more natural looking...yeah, right. They are obviously beauty lights...very blue-red>>purple. All the orange in the store really stands out now as it fluoresces. So the perception is that things are brighter. I told the manager that if they instead invested in electronic halide ballasts and higher K bulbs (6500K instead of the 3000-4000K bulbs they use now that do give off a good, but slightly yellow-green look) they could have saved themselves some loot and it would look even better. Wattage-wise, there is very little change. At 54 watts per bulb, 6 per fixture, and 6 per aisle, thats 1944 watts in an aisle that once had 2000 watts of halide....oh my, a whole 66 watts less. But it does look brighter considering the wattage...
But thats because the new fixtures have actual polished reflectors, where the old halide high-bays had nothing but plexi bell-sheilds around them that didnt focus any light downwards. Im sure if some decent bell-reflectors would have been used on the old halides...and some higher K bulbs, the results would have been even that much more impressive than the new retrofit. Im sure HD has lots of money to waste on replacing lighting fixtures and has to spend it or pay it in taxes anyways...so why not. Of course, they could pay their employees more and spend it that way, but no, they are wasting it on a new lighting system that will result in more wasted money for an inferior product. On top of that, the ballasts are a HD patent with Cooper Lighting, due to the 480v rails they need to work in. The ballasts are blowing. About one in eight needs 'tweaking, so as of right now, 1/8 the bulbs in the store are blown. Great technology. On the upside, the T-5s might not make as much heat as the halides, so maybe the store will be cooler in the summer, but other than that, this venture by HD has been very informative about the benefits of T-5 vs. halides. Im sure that they make good actinics, and offer an intensity better than PC bulbs, but Im not sold any more.
AJtheReefer
New member
Heat generation along makes the T5 worth it for me.
manderx
New member
the whole penetration thing is out the window when you have that many bulbs over that big an area, and especially on such a relatively short tank. yes, the light field disperses with distance more, but with all that overlap, what disperses away from one lamp's field approaches another's, so there is no actual effective dispersal (except near the edges of course).
i personally think this lighting is extremely underrated in terms of SPS growth. MH illuminates small hotspots on the tops of the coral branches that are probably getting too much light and photoinhibiting, and casting shadows within the colony where it's probably not getting enough light to meet it's compensation point, and has to rely on the rest of the colony for energy (ie: stealing from the potential growth rate). dispersed lighting like this will fill in every nook and cranny evenly, so more surface area of the coral is efficiently photosynthesizing rather than the feast-or-famine that SPS gets under a point-source light. remember that in the wild, the sun is moving so there aren't permanent shadows on certain parts of the coral like there are in our MH tanks.
this is the same reason i prefer SE bulbs in spider reflectors to DE bulbs (even though i do have DEs at the moment).
i personally think this lighting is extremely underrated in terms of SPS growth. MH illuminates small hotspots on the tops of the coral branches that are probably getting too much light and photoinhibiting, and casting shadows within the colony where it's probably not getting enough light to meet it's compensation point, and has to rely on the rest of the colony for energy (ie: stealing from the potential growth rate). dispersed lighting like this will fill in every nook and cranny evenly, so more surface area of the coral is efficiently photosynthesizing rather than the feast-or-famine that SPS gets under a point-source light. remember that in the wild, the sun is moving so there aren't permanent shadows on certain parts of the coral like there are in our MH tanks.
this is the same reason i prefer SE bulbs in spider reflectors to DE bulbs (even though i do have DEs at the moment).
horkn
New member
funny thing is that there are motorized tracks for lights...saw them on sun light supplys website..
since my current tank is only 18" high, and only 35 gallons, i went with t5s.. i didnt want a heat issue, and the money spent on electricity will be less.
a side note... your cube is awesome maxrep
since my current tank is only 18" high, and only 35 gallons, i went with t5s.. i didnt want a heat issue, and the money spent on electricity will be less.
a side note... your cube is awesome maxrep
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