Ultraviolet Pools was established to reduce exposure to pool chemicals. A UV system added to a pool will make the pool a much healthier swimming environment.
UV from the sun isn't the same as that used in sanitation. UV-A make up most of the sun’s light causing premature aging of skin. UV-B rays are the main cause of sunburn and stronger than UV-A. UV-C (germicidal UV) rays are filtered out by the atmosphere and never reach the earth.
Pool and Spa News (Jan 2017), “…the (UV) disinfection market will expand to an estimated value of $2.5 billion in 2019...The surge is.. due to the replacement of traditional chlorine-based disinfection with UV technology ..that many .. see as a lower-cost maintenance option.”