Signs that a bulb is on its way out or issue with my fixture

[Husker21]

I have a 2' Ultra Grow running T5s. I have them plugged into a timer that is plugged into a surge protector. The first set of bulbs I installed back in July are starting to get dim. If I swap the bulbs around or pull them out and reinstall them they will brighten up for a bit... But they seem to get dim again.

How long should a T5 last me? Or is there an issue with my fixture causing the bulbs to not be making good contact in their slots or some kind of issue cutting the lifetime of my bulbs? I have been using GE bulbs, 6400 and 3000k. A friend of mine gave me a blue bulb and man does it kick the crap out of the GE bulb I purchased. He is an aquarium guys so he knows good bulbs and gave me these bulbs that he hasn't used in years.

Ultimately I want to know if this is a normal life span of my bulbs or if there is another issue with my fixture killing off my bulbs.

Thanks!

 

[Scovie]

There are really only two things that can be wrong. Bulbs and the Ballast. Usually either will just go out, not slowly die.
Maybe it's one of your power source accessories.
I would try troubleshooting in this order...

1. Run the light plugged into the surge protector but eliminate the timer.
2. Switch the timer for the Surge protector.
3. Eliminate both, run the light plugged directly into the outlet.
Still happening?
4. Get new bulbs.
5. Get a new ballast ($20. +/-)
6. Shoot the damm thing and get a new light.