# Bulb question/poll...



## Bert H (Mar 2, 2004)

PC flourescents - I have heard folks who say 'don't change them until they burn out', others that say to change them yearly. So, I thought I'd post a poll/question - how often do you change out your pc's? Rationale for doing so?


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## Themuleous (Jun 6, 2006)

Yearly, just so I know the output is ok. It is probably ok to run them until they die but I like to be on the safe side.

Sam


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## The Bamboozler (May 15, 2007)

My tank is new, but I'll change mine at six months.


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## cs_gardener (Apr 28, 2006)

I don't have a set time when I change my bulbs. I don't let them burn out but I do go over a year with them, mostly because I lose track of time. If I notice I'm having problems with plants that were previously doing well and I can't pin it on neglect/lack of nutrients, it's time to change a bulb.


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## Left C (Jun 14, 2005)

I like to try different bulbs on my tanks to change the look. I've got right many used PC's. I believe that I've only had one PC burn out in about the past 9 to 10 years. Now, I'm going to let them burn out or I notice dimming before replacing them since I have many back up PC's.


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## John N. (Dec 11, 2005)

2-3 years then replace. Simply because the bulbs are dimmer and don't brighten the tank as much as it could. 

From my experience, the bulbs' 'brightness' decline has no noticable effect on plant growth, and probably could grow plants just fine until they stop working.

-John N.


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## Jimbo205 (Feb 2, 2006)

I don't feel guilty now. Thank you John N. !

My plants look good. And I got my bulbs in Feb 2006!


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## tfmcder (Feb 22, 2006)

I shoot for once a year or every 18 months but I usually forget so it falls between 18 months to 2 years. I am yet to have one burn out on me(knock wood), but even if one does I have about 10 or so spares sitting in my "forgotten tank" cabinet.


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## trenac (Jul 16, 2004)

I picked other because, up to know I was letting them go for as long as they lasted. Until one day I notice how yellow my tanks looked; so I bought some new bulbs. What a difference they made, crisp clean colors. Also comparing them side to side you could see how worn and discolored the old bulb was. This convinced me to start changing the bulbs out yearly, at least at a 1 1/2 years.


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## DonaldmBoyer (Aug 18, 2005)

Six months on the dot. I write the date on the bulb when I install it, and change it no matter what. It was the way I was raised in the hobby!  I've read in several books that the color of the spectrum changes as a bulb gets older; starts shifting to the red wavelengths and dims even though the eye can't perceive the change in the output. Seems to make sense to me!


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## 180gz71 (Apr 13, 2007)

Once a year, just for the sake of knowing theyre new.


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## Laith (Sep 4, 2004)

DonaldmBoyer said:


> ... I've read in several books that the color of the spectrum changes as a bulb gets older; starts shifting to the red wavelengths and dims even though the eye can't perceive the change in the output. Seems to make sense to me!


As far as I understand, that was true of T12s and T8s. PC/CFs (and T5s) apparently don't have that issue.

I don't use CFs but I've never changed out my T5s and the oldest is probably about two years old. Haven't noticed any detrimental effect on plants or plant growth.


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## Newt (Apr 1, 2004)

Every year as the output decreases significantly even with T5 technology. You can't escape cathode tube decay. T12/T10 and T8 linear fluorescents every six months. Set time schedule.

I do believe that even in CFs/PCs the color spectrum can shift. I know for certain that linear T12/T10 and T8s do.

Triton tubes by Interpet (T10 linear) claim that theirs don't degrade or shift and can be used until they fail. However, they don't tell you how they are the only ones that can accomplish this.


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## DonaldmBoyer (Aug 18, 2005)

Yeah....I was brought up using those old, "super-bulb" T12's or T8's (can't remember), and I just got into the habit of changing them every six months. I could tell that they were getting older because as they aged, the more algae I was getting on the glass. So, their output wasn't the same. Laith, I agree with you, and if you don't have any detrimental effects, then by all means, keep using the same tubes and save yourself some cash!


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## Jimbo205 (Feb 2, 2006)

The more I read this poll, the more I realize that I need to purchase at LEAST one new bulb and think of replacing both. Heck, at one point I thought I had MORE than enough. 

Of course, I DO need to spend some major time 'harvesting' and trimming my plants and ship all the trimmings to a good home.....

Thank you for this poll. Reminds me of something I guess I need to do.


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## Bert H (Mar 2, 2004)

This poll helped me decide to change out the 96W cf I had. I ordered the bulb from AHS and installed it yesterday. Boy, what a difference! Tank looked like a champagne glass last night, something I hadn't seen in a long time. From now on, I will change them out yearly. Now I just have to recall when I installed the two 55W's I have on my other tank...


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## rohape (Feb 7, 2005)

I chose once a year. It's my birthday present/ reminder.


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## ruki (Jul 4, 2006)

I replace them whenever, usually between one and two years. I don't wait for them to burn out, but sometimes I notice things are getting a bit dim and switch them then. I really should follow a schedule as some here recommended.


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## snowhillbilly (Mar 29, 2006)

It depends on the brand and its hours of use warranty. I take the expected life and cut it in half. I run my light 10 hrs a day. With T5 lighting this means you would replace about every 2 years for peak lighting. Ill see if I can find the link from GE new bulb line.


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## jaidexl (Jan 20, 2007)

I've only been planting tanks for a bit over a year, but I plan on running my pc's until they die.


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## Newt (Apr 1, 2004)

Wow, I'm really surprised at the results of this poll considering all of the available literature regarding fluorescent tube decay.


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