T5 question

EMV7904 · 10/19/2008, 08:46 AM

Do the T5 bulbs in my lighting fixture 'go bad'? Someone told me that they are good until they burn out. I gotta question this...they seem awfully weak to me. I have 4x39 watt 420nm and 4x39 watt 460nm and they just don't seem as bright as before. If they DO need replacing, how often? I believe I've been using them since 2-07. Time for new bulbs? The metal halides have been replaced once a year, but not the T5's as again someone told me that they don't wear down.

???

dukenukem · 10/19/2008, 08:53 AM

The replacement interval for T5's is 1 year I believe, and less if they are overdriven. As the bulb wears out, the spectrum changes increasing the possibilities on neusance algeas.
HTH....

cilyjr · 10/19/2008, 09:12 AM

the spectrum will change a bit and they will lose intensity over time...
i always changed mine every year and 1/2 when i was running them

IslandCrow · 10/19/2008, 10:47 AM

12-18 months seems to be the standard. I change mine out yearly. I don't know if any real research has been done on loss of PAR and/or spectrum shift over time. Since it's been so long for you, I'd suggest swapping them out a couple bulbs at a time and waiting at least a couple weeks between swap outs. That's just if you have corals so you don't change the overall light intensity of your tank too quickly.

m2434 · 10/19/2008, 10:50 AM

Mnay companies seem to advertise 2years, but many change them out 6-12 months. I agree this depends if they are overdriven.

GoBigOrGoHome · 10/19/2008, 10:59 AM

Maybe I'm crazy, but I've heard that overdriving the bulbs can actually cause a delay in spectrum failure due to increased current running through the bulbs... sounds kind of counter-intuitive, but that's what I heard.. I've had mine running overdriven for 1 year+ without problems now, and the actinics still bring out the same crazy greens.... and the first set of bulbs I had were in there for about 17 months or so before changing... granted, I was battling hair algae, but I certainly don't think that the bulbs were a large contributor to the problem.

nikon187 · 10/19/2008, 04:18 PM

every 12 mths here as well. I wouldn't overdrive bulbs without fans and yearly bulb changes.

10/19/2008, 08:46 AM	#1
EMV7904 Moved On Join Date: Oct 2008 Location: US Posts: 203	T5 question Do the T5 bulbs in my lighting fixture 'go bad'? Someone told me that they are good until they burn out. I gotta question this...they seem awfully weak to me. I have 4x39 watt 420nm and 4x39 watt 460nm and they just don't seem as bright as before. If they DO need replacing, how often? I believe I've been using them since 2-07. Time for new bulbs? The metal halides have been replaced once a year, but not the T5's as again someone told me that they don't wear down. ???

10/19/2008, 09:12 AM	#3
cilyjr Registered Member Join Date: Sep 2006 Location: Rhode Island Posts: 1,683	the spectrum will change a bit and they will lose intensity over time... i always changed mine every year and 1/2 when i was running them __________________ Cls Current Tank Info: 180 inwall, 75 sump, 20lfrag, 3x lumen max elite w/250w radium 20k, recirc modded asm g-3, aqua controller apex,2x rw-20, 350lbs LR

10/19/2008, 10:47 AM	#4
IslandCrow Reef Monkey Join Date: Sep 2005 Location: Rockledge, Fl Posts: 5,759	12-18 months seems to be the standard. I change mine out yearly. I don't know if any real research has been done on loss of PAR and/or spectrum shift over time. Since it's been so long for you, I'd suggest swapping them out a couple bulbs at a time and waiting at least a couple weeks between swap outs. That's just if you have corals so you don't change the overall light intensity of your tank too quickly. __________________ All opinions in the above message should be taken with 35 ppt salt. -Mike C. Current Tank Info: I have a reef screen saver on my phone, does that count?

10/19/2008, 10:50 AM	#5
m2434 Registered Member Join Date: Jan 2004 Posts: 2,171	Mnay companies seem to advertise 2years, but many change them out 6-12 months. I agree this depends if they are overdriven. __________________ Our imagination is stretched to the utmost, not, as in fiction, to imagine things which are not really there, but just to comprehend those things which are there. ~Richard Feynman

10/19/2008, 10:59 AM	#6
GoBigOrGoHome Registered Member Join Date: Sep 2008 Location: WI Posts: 641	Maybe I'm crazy, but I've heard that overdriving the bulbs can actually cause a delay in spectrum failure due to increased current running through the bulbs... sounds kind of counter-intuitive, but that's what I heard.. I've had mine running overdriven for 1 year+ without problems now, and the actinics still bring out the same crazy greens.... and the first set of bulbs I had were in there for about 17 months or so before changing... granted, I was battling hair algae, but I certainly don't think that the bulbs were a large contributor to the problem. __________________ Check out my little red house. 8000-gallon tank build in progress Current Tank Info: 15 tanks of varying sizes, 8-110 gal, 11 fresh, 4 salt

10/19/2008, 08:53 AM	#2
dukenukem Registered Member Join Date: Aug 2007 Location: San Diego, CA Posts: 26	The replacement interval for T5's is 1 year I believe, and less if they are overdriven. As the bulb wears out, the spectrum changes increasing the possibilities on neusance algeas. HTH....

10/19/2008, 04:18 PM	#7
nikon187 Registered Member Join Date: Jul 2008 Location: Edmonton Alberta Posts: 4,717	every 12 mths here as well. I wouldn't overdrive bulbs without fans and yearly bulb changes. __________________ ----------------- Current Tanks: New 210 custom 84 x 24 x 24, 60g sump, SWC 250 extreme with bubble blaster 5000, 2 vortech mp40, 2 vortech mp10, 12 T5, Water blaster 5000, warner marine bio pellets, 60g clownfish cube, red carpet anemone with a 25g sump,SRO octopus 1000sss, 250w radium, lumenarc large.