# What's the realistic life of a t5HO bulb?



## Scouter (Mar 3, 2008)

Hello everyone, I've been wondering when I will need to replace my bulbs. I know the manufacturers say that their bulbs last for x number of hours, but I have a hard time believing that the bulbs actually produce good growing light for that long. When do you start replacing bulbs? I'm running giesemann bulbs right now.

Thanks,
Scouter


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## TAB (Feb 7, 2009)

that really depends. generally its 6-9 months before there is a drastic color shift.


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## niko (Jan 28, 2004)

I've used the same T5HO bulbs since 1879 - the same year Edison invented his incadescent bulb.



Just joking, I do not know how long a T5HO lasts.

But what I do know is that if you keep the same bulb forever the plants adapt to the gradually diminishing light. You can go on with the same bulb for literally years. Some plants will not grow but the ones that are established will. I've done that with T12VHO bulbs that were literally 40% of their initial intensity. They were 7 years old when I replaced them.

Of course there is a logical end to this and also one does not need to be that crazy cheap so to not change a $20 bulb when it has to be changed.

--Nikolay


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## bosmahe1 (May 14, 2005)

In some cases, the new bulbs may have had more PAR then you really needed to begin with so, depending on your requirement, you might still be happy with them a year and a half later. I have some bulbs where the ends are visibly blackened they grow plants more than adequately.


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