T5 Fixture only lighting with certain bulbs

[xnick87]

This morning my Coralife T5 fixture didn’t light up when the timer came on. Like no flicker, nothing even tries to start up. It’s a 24” dual bulb fixture thats 4 months old . Currently running 2 ATI bulbs that are 2 months old. So I took it apart and discovered that if I use my old Coralife bulbs or any old bulb and my one ATI coral+ bulb, both bulbs light up and it works. If I use the blue + bulb with an old Coralife bulb they will flicker and act like it wants to start but neither light up. Is this a sign of a bad ballast? Or could the one ATI bulb be bad and taking down the whole fixture? I remember having a bulb burn out on an old fixture and the one good bulb stayed lit so this is confusing me. I know ATI bulbs are significantly stronger so I’m wondering if my ballast is almost cooked and can’t handle running 2 ATI bulbs at once. Thanks in advance!

 

[A. grandis]

Assuming that your fixture is made for HO T5 bulbs... probably the Blue Plus bulb is defective. Call the store and tell them what's going on. They should be able to replace the Blue Plus for you.