I have a bank of 12 t9 bulbs. I would like to purchase some ballasts, however, t9 ballasts are no where to be found except for circline bulbs. I have straight tubes. I would like to know if I can use instant start t8 or instant start t10 ballasts. Or if anyone knows where to find instant start T9 ballasts that would be helpful as well

Thanks -J

  • What the rest of the number on the bulb F??T9?????
    – Tyson
    May 25, 2016 at 21:18
  • F20T9/BL 20W Fluorescent Blacklight Bi-Pin Base
    – jason
    May 25, 2016 at 22:10
  • I just googled F20T9 ballast and found quite a few choices.
    – Tyson
    May 25, 2016 at 22:19
  • Everything I'm seeing is a circline ballast with connector. That is for circular flourescents, I need ballast for tubes, which I still havent found.
    – jason
    May 25, 2016 at 22:22
  • 1
    Yea for instant start you'll have to move to T8 it appears T9 only has magnetic ballasts available.
    – Tyson
    May 25, 2016 at 22:57

2 Answers 2


Here is a 18-20W black light balast there are others. make sure to google the entire number F20T9/BL and look for the bi pin models. (You will get less hits on circle lamps with the BL as that is a standard bi pin).


T9 is a very odd size. Switch to T8 -- it's very common. If you could find T9 ballasts, they would probably cost more than a T8 ballast plus T8 tubes. The sockets are probably identical.

Better yet, look into replacing them with LED lighting. You can get retrofit LED tubes that fit fluorescent fixtures, and the cost probably isn't much different than new ballasts and tubes.

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