The F15 T8 is starting to end blacken a bit. So for a new bulb, which F15 T8 fluorescent tube is better? GE, Phillips, or Sylvania?

Heres a pic of it.  
http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=1&pid=141438

Sylvania seem to work well for me... someones probably gonna shoot me down on that one though...

In my experience, F15T8's start end blacken pretty early in their life. So it still might have long way to go. But this is just my experience with european lamps and 230v chokes.

I've had excellent results with Philips Alto that are made in Holland. In fact, I have one on 24/7 duty and it was installed in the summer of 2011 and still going, with no end blackening (not visible when lit, at least). It is running on a 120V preheat choke (China) and with a Leviton (Costa Rica) FS-2 starter.

I have found that Sylvania can be hit or miss. GE Indonesian, very, very poor life (6-9 months). Even GE USA are not that great.

I have some Hungarian GE that I installed in early 2011 in my living room and they show very slight, faint end marks. They are used about 5-6 hours a day, using the same ballasts as the aforementioned 24/7 one.

Don't Phillips Alto tubes get mercury starved, and loose their vaccum overtime, when they go EOL?

Don't Phillips Alto tubes get mercury starved, and loose their vaccum overtime, when they go EOL?

They can be hit and miss as well, some times you get a good box and they last a long time, and other times they die in a week, most of the modern stuff ain't like the older stuff was and sometimes it's not even close..

All round if your tube has a little bit of blackening just run it till it dies and enjoy it while you can, I used to look for it many years ago, now the only time I notice it, is when the light doesn't turn on but none of my florescent tubes are vintage or really special and I have lots of spares from the re-store...   

For Alto lamps, I believe a lot of reliability issues revolve around where they are made. The ones made in Holland seem to be very good, others, not so much. They can be very different according to the batch...