Bulb diameter question.

[midgetwaiter]

Originally Posted by PoonTang

the "T" number of the bulbs is the size of the bulb in 8 ths of an inch. Therefore T5 is 5/8 " diameter and T12 is 12/8" . They all have their own specific mounting caps.

There's a bit more to this.

The diameter is important when using water resistant endcaps as you need the right spacer to ensure a seal. Most of the end caps on the market actually have interchangeable seals if you are going to use a T8 or T12 in them. You should be able to find these somewhere.

The option you have if you don't want to switch your end caps is to track down some T6 HO bulbs. They will be fine on your 54w T5 ballasts and use the same pin placement as a T8/T12 bulb so your end caps would work with the right seals. They are actually really great bulbs but kind of tough to find. Getting T5 end caps might be easier.