Bulb Replacement

[dwdenny]

When does everyone change the bulbs in their nano cube? I was tinking changing at about 9-10 months to keep the intesity up in the tank.

[doncb]

I think 12 months is the norm. The main reason is that as lamps age the wavelengths shift. The intensity (brightness) drops off but that isn't really the reason for replacing the lamps.

[audiocontrol]

I have heard stories of PC bulbs losing half of their intensity after 6 months, anyone verify that?

[doncb]

Originally posted by audiocontrol

I have heard stories of PC bulbs losing half of their intensity after 6 months, anyone verify that?

 

Remember there is a difference between intensity and wavelength. I used to work in a field where we used high UV output FL lamps. The lamps would "look" as bright on day 365 as day 1 but the UV output had dropped 20% - 30%. Same for the mercury vapor lamps we used (kind of like MH's). Unless you have a meter you can't really see the shift.

 

I'd replace the lamps @ 10 - 12 months, no mater how "bright" they look. When the wavelength output has shifted enough you can get alge growth, etc.

 

my .02 anyway.

[dwdenny]

Originally posted by doncb

Remember there is a difference between intensity and wavelength. I used to work in a field where we used high UV output FL lamps. The lamps would "look" as bright on day 365 as day 1 but the UV output had dropped 20% - 30%. Same for the mercury vapor lamps we used (kind of like MH's). Unless you have a meter you can't really see the shift.  

 

I'd replace the lamps @ 10 - 12 months, no mater how "bright" they look. When the wavelength output has shifted enough you can get alge growth, etc.  

 

my .02 anyway.

 

That is what I was told about the spectrum. I was planning on changing them every 10 months anyway but I was just making sure that I was thinking in the right direction.