# How often do you change your lighting tubes ??



## Greenfinger2 (26 Aug 2015)

Hi All, How often do you replace you plant tubes ??


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## Greenfinger2 (26 Aug 2015)

Only there is one school of thought that there is no need to replace tubes till they burn out ?
and another that says you should change them every 9 months ??



*Bulb Life Expectancy*
If you are only keeping fish in your aquariums, you only need to replace your light bulbs when they burn out, and this varies from bulb to bulb. If you are using N.O. fluorescent lights, you should replace the starter each time a bulb burns out, as often a burnt out bulb burns out the starter as well. If you are raising live plants or corals, you should replace your N.O. fluorescent lights every 5-7 months, because the intensity of the light begins to fade and it looses its helpfulness to the plants or animals that need it. You may not see this difference until you replace the bulb, but it certainly makes a difference to the plants or animals that depend on it! If you are doing this, remember to replace the starter(s) at least once a year. If you are using power compact or V.H.O. fluorescent lights, you should replace the bulbs about once a year, or whenever the bulb burns out. These bulbs are better able to maintain their spectrum over time, and do not degrade as fast as N.O. fluorescent bulbs. Metal halide bulbs should be replaced every 8-12 months. When changing M.H. or V.H.O. bulbs, remember to check the ballasts to see that they are working well and are not overheating or showing any other signs of wear. If there are signs of wear or other problems with the ballasts, they should be replaced at the same time.


So what method is right ????


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## Tim Harrison (26 Aug 2015)

If you're happy with the colour rendition and plant growth why change them? Which I think is pretty much the general consensus.
I've had the same T5 and T8 bulbs for donkey's years and only usually change them when they burn out or start to do strange flickery things...


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## ian_m (26 Aug 2015)

Here is a typical graph of lumen vs time for a T5 tube.

So down to 90% level after over 15,000 hours. If you have yours on typically 8 hours then that's 5 years.

Other things fail usually before lumen maintenance becomes an issue,  namely ballasts, controllers, tube heaters and moisture ingress. If not using a modern electronic starting ballast (one wire to each end) then the tube heaters are the weak link by a couple orders of magnitude.


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## Greenfinger2 (26 Aug 2015)

Hi Troi, Well you learn something every day  When I ran tubes I changed them every year I even put the date on them  Now I know better thanks for the info 

A chart from another site 

I think the chart below is quite true. After 20.000 hours, the bulbs will start to die faster. Loosing about 15% of power in the first 20.000 hours. Not sure whether dimming them would make them last longer or shorter, but lets say the same. Than with 10 hours a day, it should last 2000 days (6 years!) You want it to be above 95% of its max power, than 2500 hours (250 days)


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## Greenfinger2 (26 Aug 2015)

Hi  Roadmaster You were right I was wrong


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## alvarenga (26 Aug 2015)

usually change as the black area at the ends of the lamps increases. The latest replacing, measured with the par device device did not see big drop in power lamps with 18 months about 4500 hours.


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## ian_m (26 Aug 2015)

alvarenga said:


> usually change as the black area at the ends of the lamps increases.


The black ends is the heater element evaporating away. Also causes light drop as it darkens the whole tube. If you use an electronic striking ballast, as used by Juwel lighting (and others) they don't use the heater, just apply 1000v pulse to start the tube. Not using the heater means significantly longer life and lumen maintenance. You do get slight blackening after years this due to slight heater evaporation after being bombarded by electrons and ions.


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## Dantrasy (28 Aug 2015)

2 year old tube vs. new tube


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## Edvet (28 Aug 2015)

T8: yearly, T5; when it fails, HQI: 5 year, HQL about yearly, That's what i do, except no T8's anymore. The rest i still use.


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## REDSTEVEO (3 Sep 2015)

Dantrasy said:


> 2 year old tube vs. new tube



A picture paints a thousand words, now that's what I like,

Cheers,

Steve


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## ian_m (3 Sep 2015)

Are they T8 tubes ? Modern T5 tubes last much much longer. This weekend will take a picture of my T5 tubes, one couple months old and other over 2 years. Can only tell which is which as I have written the install date on with permanent pen.


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## Edvet (3 Sep 2015)

T5's are supposed to be good till they fail.


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## Dantrasy (3 Sep 2015)

the pic above is of T5HO tubes in an ATI power module fixture. 

all the mentions of T5 ... you mean T5HO, right?

to me T5 is is something different, a thinner tube with far lower output compared to T5HO.


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## ian_m (3 Sep 2015)

T5 and T5HO are same 16mm diameter, it's just that HO gives more lumens output per cm of length

Actually tube diameter is 5/8 of an inch (15.9mm), which is where the 5 in T5 comes from. Some countries call it a metric T16 tube.


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## dw1305 (3 Sep 2015)

Hi all, 
I think it is like "ian_m"  said, it is the electronic ballast and the triphosphor coating that makes the big difference, rather than the diameter, although the thinner the diameter the more efficient the tube is. 

Theoretically a <"linear T2 tube"> would give you most "_bang for your buck_", but they are extremely fragile in longer lengths.  

I think that all? T5 ballasts are electronic, and most are "instant start" (apply a large starting voltage across the electrode), but some of the older T8 fittings will be magnetically ballasted, and some of the aquarium tubes in strange sizes may still have halophosphate phosphors. 

There is a good summary of all you need to know here: <"Tubular Fluorescent lamps">.

cheers Darrel


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## Troglodyte (4 Sep 2015)

Hi all,
I think what you just need to keep in mind, is that the answer will depend on :-

your personal lighting preference. 
the task your are using the lights for. 
Being a planted tank forum, there is no real need to change the bulb before it pops, as plants adapt to the light being received by putting out more light receptive cells.(if I have understood it correctly?) 
Also if there is no tank depth to overcome, then it should be fairly easy to provide adequate lighting for most plants grown in the aquarium trade with T5/T8 whether it is new or old.
The real benefit between T8/T5

 is the efficiency, in favour of electronic ballasts and T5.(also less flickering)
safety, some electronic ballasts can be IP68 compliant. All magnetic ballasts that I know, are not.
NB. There is an EU work remit that will be removing all T8's and magnetic ballasts from production, pretty much like the filament bulb, by 2017( I think?) and  T5s some time after that.


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## ian_m (4 Sep 2015)

Troglodyte said:


> There is an EU work remit that will be removing all T8's and magnetic ballasts from production


That's going to be very very expensive. We just paid £7.50 each (in bulk) for 600x600 office ceiling light fittings with 4 x T8 tubes fitted and magnetic ballast, to replace failed units in our new offices. Cheaper than replacing tubes and/or ballasts, buy & fit new unit. Did look at T5 units but starting at around £30-£40 each and LED's, as well as not as being so bright, started at £60 each.


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## ian_m (6 Sep 2015)

Well here is the picture. Juwel Vision 180 lighting unit purchased Feb 2013, came with spare tubes. All tubes High-Lite Day. Had to turn camera brightness right down as both tubes extremely bright.

Tube on right is 30 months old and one on left is 6 months old. Possible slight differences in brightness, but hardly significant.


 
This is contrary to my experiences with Juwel T8 tubes, especially, Acardia T8 were better, that it became really obvious after a year that that brightness was falling.


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