PA Series Ultraviolet Disinfection Systems-Silver Series. This modular line of ultraviolet disinfection systems can be used in a myriad of applications where flexibility and pricing sensitivity is a deciding factor. The small SQ-PA through S2Q-PA systems are ideally suited for point-of-use filtration, RO pre or post disinfection, while the larger S5Q-PA, S8Q-PA and S12Q-PA systems can be used on a point-of-entry system, disinfecting the water for an entire home or cottage. The low pressure germicidal lamps provide an economical way of treating water requiring a 99.99% reduction in bacteria and viruses.