Then your U.V needs to be a 30" tube as for the percentage of the tube, well thats a bit of a grey area, some say they need it some say they dont, personally I would go with a 5% output, it's not the highest but will get what it needs if it's needed.
hi mate just took my stack down got a few bits and bobs i have 2 controllers here looking for a tenner a piece im at bishop auckland if any good to u what else you after cheers darren