Arcadia D3 UV Tube Problem

[KurtH]

Hi all,

I installed my Arcadia D3 UV Tube about 5 days ago and tonight it seems really dim. It should at least light up the viv shouldn't it?
When I installed it, it was almost unbearable to look at!
There is also a purple spot at the end of the UV Tube....could it be faulty?
Here is a pic of the bulb turned on and the mysterious purple dot....

Any ideas?

Thanks in advance