Longevity of T5s?

[NewMariner]

Just out of curiosity what has everyones longevity been running on your t5s? I have a Tek 4 bulb 39w fixture. I bought a geissman aquablue bulb and it seems to have burned out after about 6 months of use. My lighting schedule is just 10 hrs a day...These bulbs arent that expensive but I just thought they would last a little longer then this...

[aninjaatemyshoe]

That depends. The Tek fixtures don't actively cool the bulbs. So they won't last as long on that fixture as say on an Aquactinics Tx5, which has a fan that actively cools them. Most data I've read on them points to being able to use them for up to a year and a half. If you overdrive them with an Icecap ballast, the lifespan is reduced to 1 year.

[NewMariner]

Anyone else have any actual experience?

[ROB2005]

Mine lasted for 17 months with normal use. I dont overdrive my T5's.

[jayke]

Mariner,

I have the exact same fixture as you. I found that the Geisemann lamps lasted about 1 year 4 months for me with a 10 hour cycle per day. After that, my tank was noticeably a bit more yellow and some nuissance algae began to pop up. I since replaced the lamps with UVL and ATI lamps (very happy with their output). I would say that the lamps in a Tek fixture would be good for about 1 year to 18 months, but to be on the safe side, I plan to replace mine after 12 months.

Jay

[NewMariner]

<a href=showthread.php?s=&postid=10981697#post10981697 target=_blank>Originally posted</a> by jayke
Mariner,

I have the exact same fixture as you. I found that the Geisemann lamps lasted about 1 year 4 months for me with a 10 hour cycle per day. After that, my tank was noticeably a bit more yellow and some nuissance algae began to pop up. I since replaced the lamps with UVL and ATI lamps (very happy with their output). I would say that the lamps in a Tek fixture would be good for about 1 year to 18 months, but to be on the safe side, I plan to replace mine after 12 months.

Jay

Interesting...Maybe I just got a bad bulb or something..I dunno...where did you get the UVL and ATI lamps? I havent found those at reefgeek...

[jayke]

Just ordered mine from Reef Geek, just got them in last week. Fast shipping

[tgreene]

T5's are good for 6 months tops, due to spectral degradation. The only way to actually track this is with a Par or LUX meter, because the human eye cannot differentiate the most subtle changes.

While the actual filament itself can certainly remain functional for a period of 18-24 months, the effectiveness of the bulb is toast!


The image below is of my 72" tank which uses (4) 36" T5 bulbs on either side, for a total of (8) bulbs... I only ever use UV bulbs in a ratio of (3) 420nm Super Actinics to (1) 12k Actinic White -- The bulbs on the left side had just been replaced, while the bulbs on the right side were just over 6 months old.

Again, the only difference between the left and right side of the tank, is the age of the bulbs.

http://www.nea-reefkeeping.com/images/bulbs/105.jpg



* I realize the image sucks, but it's the comparrison that matters. ;)

-Tim

[NewMariner]

Thanks Tim for the visualization. Although I perfectly understand bulb degredation and the usefulness of the light, my bulb, which was an actinic, not my 6500k bulb, burned completely out. As in now I have 2 bulbs not firing due to one of those bulbs being burned. I was under the assumption that these bulbs would last 18 months or so, and would need to be replaced before then. However that was not the case..it simply died after 6 months of use.

[tgreene]

There are far too many variables to be able to say why that happened, so I would simply call it bad luck.

I go through about (50) T5 bulbs per year, due to the size of my two systems, with one using 8 bulbs, and the other using 14... As for the remaining 6 bulbs, sometimes they just pop. I've had them misfire and burn out due to power dips, as well as have them explode due to power spikes. Heat, salt creep, pin corrosion, bad pin weld, etc. can all be contributing factors, which is why I keep several spares on hand at all times.

I know this isn't what you wanted to hear, but it's reality.

-Tim

[hahnmeister]

Active cooling is most important for T5s. Adding fan cooling to the Tek increased my output by almost 20%. The longevity of the bulbs depends on it heavily as well. My bulbs were 18 months old in the end and still chuggin along like they would have hit 2 years w/o a problem as long as they were getting cooled.

No fans? Good luck lasting 6-9 months.