# How often do you change out your T5HO light bulbs



## saucynoodles (Sep 29, 2011)

For what it's worth:
I think the "lack of flow" thing is a myth with CB. I had a nice colony growing on the spong that covers the intake for my circulation pump (one of the top 4 HIGH flow areas in my tank). While I was fighting my CB, I was told by a planted tank enthusiast that CB can break out in any tank for any number of reasons. I know this doesn't address your T5HO question, but I am also curious what that answer is!!!


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## Optix (May 31, 2011)

I replace mine once a year

...as the bulbs burn, the spectrums shift...so, visible light may not be a needed or useful "color" for plants


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## bradlgt21 (Mar 24, 2010)

That is what I have always done with my T5NO bulbs if they make it to a full year, lately they have been popping at a few months.

But for what its worth I noticed most of the bulb manufacturers are claiming longer life out of there bulbs. I have seen 10,000 hour claims which come out to be almost 3 years depending on how long you have them on. I have also seen 18-24 month claims, whether you believe the manufacturer claims or what you hear around here thats up to you.

I have found that I don't start seeing problems until about 16+ months. Whether that means they died out at 12 months and it just took that long to effect the plants or if it really did last 16 months before losing its effect I don't know.


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## BBradbury (Nov 8, 2010)

*HO Lights*



gotplants said:


> I recently got a little bit of cyanobacteria in my tank but got rid of it before it got out of hand. I'm stopping the medication tomorrow and putting back my carbon and purigen in tomorrow. I'm not sure if it's the old light bulbs or lack of flow in my tank that caused the cyanobacteria to grow. I had my Eheim outlet low but recently raised it since starting the medication and will keep it raised so it's half way above the water level because I know lack of flow also causes cyanobacteria. My light bulbs are 15 months old and still work. Should I replace them or will I be able to keep them without having the cyanobacteria come back? I'm pretty sure I corrected all the other problems I had that could have possibly caused it to form.


Hello got...

If you have demanding plants needing high end lighting, you should replace the bulbs every 8 to 10 months. High output lighting intensity will drop over time and affect plant growth.

If you have low to moderate light plants like me and use T8s and T12s from the hardware store, then those bulbs can last well over a year with no affect on the plants that I can see.

B


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## Hoppy (Dec 24, 2005)

The problem with determining how long fluorescent bulbs will last is that there is no requirement on the manufacturers for them to last any longer than the stores will guarantee them. A few years ago I had some data that suggested that the T5HO bulbs in use by that particular person would last over 2 years, but not much over that. But, screw-in CFL bulbs used to last for several years, and few of them do that anymore. We all tend to buy the lowest priced option when we buy commodity type products. That forces manufacturers to cut corners on quality to keep their prices low enough. The last CFL bulbs I bought lasted a few months only. And, a 13 watt square pin power compact bulb I bought last, only lasted about 3 months, even though the original had lasted about 5 years.

I suppose I could have just said, "I don't know how long they last".


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## plantbrain (Dec 15, 2003)

Optix said:


> I replace mine once a year
> 
> ...as the bulbs burn, the spectrums shift...so, visible light may not be a needed or useful "color" for plants


Plants are very adaptive to available light and spectra. So when the bulb shifts, so do the pigments that plants use to catch light.

Water color changes and filtering from other plant species and the same species self shading etc all occur and they adapt to this easily, no reason why this would not occur with older bulbs.
As long as the nm is above 680nm or thereabouts, likely okay. But that would be a blood red weird bulb.


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## Psionic (Dec 22, 2011)

Just yesterday this was brought up in other forums. I said that after 6 months, t5ho lights will slightly change very little from that point on. I was told I was not correct and that only happens to t8 and t12 bulbs. They said that t5ho bulbs last 12-18 months and nothing changes with them. Is that true?

From what I've read, t5ho bulbs do change their spectrum as time goes by and the lights get older, correct? Even if the lights do last 12-18 months, they won't be the exact same as when they were first installed? 

Also that the same 6500K lights from one brand can be different from another even if they're the same temperature. I mean like comparing giesemann to lowes.


-Val


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## Jeff5614 (Dec 29, 2005)

I usually change mine once a year. I don't know what the change is, whether it's intensity, color, etc., but there's always a difference in appearance even though I've been using the same brand ( Giesemann Middays ) for a few years now. They look brighter and crisper. I don't know if the plants notice or care but I prefer the look of the tank when the bulbs are new.


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