One last bit of advice - UV lights CAN provide one benefit that VisSpec lights don't, and that is antimicrobial and bacteriostatic action. Usually lower λ levels are required for this, but it does greatly reduce the risk of microbial infection to the plant (although in practical terms may not be worth the effort, time, or money). These types of lamps are often used in biohazard areas where aerosolized particles of microbes may pose a threat to personnel and the retention of living or active organisms/viral particles is not required.