# *POLL* How long do you think a T5 tube will last?



## FishBeast (21 Jan 2012)

I am interested in knowing as the growth in my tank has slowed alot over the last few months.


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## foxfish (21 Jan 2012)

This has been discussed before & generally folk tend to change every year however it is believed by many, that they last for "many years" before any noticeable drop off in light!
At one time when T8s were more popular it was recommended to change them every six months but this does not seem to apply to T5s.
Anyway I change mine every year...


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## skeletonw00t (21 Jan 2012)

For as long as it turns on...


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## dw1305 (22 Jan 2012)

Hi all,


> For as long as it turns on...


 They don't need changing, they just fail, usually when the cathode wears out (due to electron bombardment). T5 lamps are electronically ballasted and show hardly any lamp lumen depreciation (loss of brightness),  and the tri-phosphor lamps don't suffer much from phosphor depletion. You can easily get 2 or 3 years from a lamp, and with one switch on/off in any 24 hour period, live could be a lot longer, particularly if you have a 14W lamp on a 14 - 24W rated ballast etc.

Linear T5's should last longer than CFL lamps (basically twistedT5 tubes with internal control gear)

cheers Darrel


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## ceg4048 (22 Jan 2012)

Furthermore, if growth has slowed in your tank there is only a 0.00001% chance that it has anything to do with light and instead, there is a 99.99999% chance that it has to do with CO2/flow/distribution.

Cheers,


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## skeletonw00t (22 Jan 2012)

I saw in PFK this month it had a "top tip" to replace tubes every 12 months to "significantly increase the lighting over your aquarium" page 47... Seems there are still conflicting opinions on the issue of replacing tubes.


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## Morgan Freeman (22 Jan 2012)

Yeah yeah replace your tubes blah blah blah. I've had mine for 2 years and the plants are still doing great.


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## George Farmer (22 Jan 2012)

skeletonw00t said:
			
		

> I saw in PFK this month it had a "top tip" to replace tubes every 12 months to "significantly increase the lighting over your aquarium" page 47... Seems there are still conflicting opinions on the issue of replacing tubes.


As the author of that article allow me to explain.

That specific tip was in reference to a recent experience regarding an aquarium makeover.

The client had 4 x T8 fluorescents over their Juwel Trigon 350. I believe the Juwel ballasts are electronic, even the old T8 type.

The bulbs were old, at least 18 months. 2 x Hagen Power-Glo, 2 x Life-Glo.

I tested the PAR at the substrate using an Apogee meter.

With the old tubes it was less that 10umol in the corner.

With the new tubes it was over 20umol. Same brand and model type.

So as you can see that's over 100% increase in light by swapping old for new tubes. There was some hard water deposits on the old tubes but not a significant amount.

I can't comment on whether this applies to T5 and have every faith in Darrel's comments.


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## foxfish (22 Jan 2012)

This is my hobby, I want to change my dirty bulbs every year regardless!
They cost a couple of £ each & you can experiment with different colours too


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## skeletonw00t (22 Jan 2012)

George Farmer said:
			
		

> skeletonw00t said:
> 
> 
> 
> ...



I see George - I get you! I think i misunderstood it really. 

So basically - changing the bulbs will increase light & make a visible difference. BUT it wont improve a tank that is already struggling due to a co2/nutrient difficiency.


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## Morgan Freeman (22 Jan 2012)

If the bulbs did in fact increase light, those issues would become worse.


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## George Farmer (22 Jan 2012)

Morgan Freeman said:
			
		

> If the bulbs did in fact increase light, those issues would become worse.


Exactly. This is explained in detail in the article.


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## dw1305 (23 Jan 2012)

Hi all,
Most T5's should have better LLD than most T8's, but there are factors other than diameter. George's figures are very interesting, I'm not familiar with either the Juwel fluorescent tubes or Hagen fitting, but that would strongly suggest that either it is an older style ballast and/or using halophosphate fluorescent tubes. 

The combination  of high frequency electronic ballasts and T5 triphosphor tubes should lead to a lamp life of over 20,000 hours, with very high lamp lumen maintenance.






Image and quote are from http://www.lif.co.uk/lamp-guide/discharge-lamps.html#tubular-lamps


> _The life of a fluorescent lamp is measured in a number of different ways. Two measures tend to be employed: mortality (i.e. the number of operating hours elapsed before a certain percentage of the lamps fail) and lumen output (i.e. the depreciation of the lumen output over time). Both sets of data are useful measures. The rated life of tubular fluorescent lamps can range from 6,000 hours up to 60,000 hours, or more, depending on lamp type and control gear.
> 
> They can have a lifetime of up to 23,000 hours for normal T5 lamps (90% service lifetime at 12 hr switching cycle). Special long life lamps also exist where the life time is up to 68,000 hours with the same energy efficiency. Halophosphate lamps have a lifetime of only 6,000 hrs and are soon to be discontinued under the EuP Directive. All tri-phosphor lamps have a high CRI (typically >80) and are also 20-30% more efficient than halo-phosphor types with low CRIs. Better energy saving can be achieved when the lamps are operated on an electronic HF-ballast,_........



cheers Darrel


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## plantbrain (24 Jan 2012)

I have some that are about 3 years old now, they are close to those graphs, loss is roughly 8-10%, but perhaps I should wipe and clean the bulbs and the reflector a bit more before I compare the nice clean new ones vs the oldies?


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## Wolfenrook (6 Feb 2012)

Not joining the debate, as my honest answer is, no idea. lol

However thought George might find this useful info.  My old lighting on my old (now retires) Juwel Rio 180 was the old T8 stuff, and it had magnetic ballasts, with 2 chokes hidden behind screw in plastic covers on the beam, so definitely not electronic ballasts on the old T8 beam I had at least.

Hope this is helpful in some small way.

Ade


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## CeeJay (11 Feb 2012)

Hi all


			
				foxfish said:
			
		

> They cost a couple of £ each & you can experiment with different colours too


Not if they're the Juwel 45W T5's with the oddball length.   
£15-£20 a pop.    
I'll just keep using mine till they cease to function   (3 years so far  )
Then I'll rip them out and fit an el cheapo T5 ballast from lamp specs. It means moving the lamp holders because of their stupid length, but hey ho, I can then get the tubes for £3-£4 a go


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## Rasmusm (12 Feb 2012)

We have actually tested this. And result is that after 4years the tubes weares out (for plant use anyways), the guy that tested suddenly had problems with plant growth and algaes. He did nothing but changed the tubes. Month after algaes gone and plant growth was back to normal.. His t5 tubes was 4 and a half year old. This is with 9 hours of light pr day. T8 is another story.. prolly 7-10 months and they should be replaced.


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## gex23 (16 Feb 2012)

Will heat have a detrimental effect on the life of the bulb? Very interested to see the potential life of these bulbs - much longer then I originally thought


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## ste_v5 (16 Feb 2012)

i will be running 2 marine white bulbs that are over a year old so will let you know


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## Rasmusm (16 Feb 2012)

Yea i think the lifetime they say is at 35degrees celcius. Not sure though


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## dw1305 (17 Feb 2012)

Hi all,


> Will heat have a detrimental effect on the life of the bulb? Very interested to see the potential life of these bulbs - much longer then I originally thought


The T5's run a bit hotter than the T8's, I think Rasmusm is right and the rated life for T5's is at about 35oC. <http://www.theaquariumsolution.com/optimum-working-temperature-t5-tubes>.

Cold temperatures have quite a deleterious effect on lamp life, and they have special fitting for freezers. 

cheers Darrel


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