You could go for uv led strips instead of the cold cathodes?Just a little update regarding the cathode tubes:
They don't like being vertical. I have had to replace 4 tubes that I have mounted vertically in the case have rapidly dimmed to almost emitting no light at all, while the 2 I positioned horizontally have shown no sign of failure since the day I fitted them.
I am considering changing my tubing out to transparent and using an orange pastel for the next time I flush the loop.