ok well its always good to have a back up bulb -- I always keep 2 on hand as I have two tanks and change those bulbs out every 10-11 months- I have gotten dud bulbs - I use both the Reptisun and the Arcadia bulbsLast time I checked they didn't have T 5, that's why I ordered one online. Anyway I am pretty sure the T 5 fixture shorted out.