I should add that the UV / H2O2 system I installed ended up working poorly, because the pool was 200 miles away, and the owner decided to turn pool care over to the property manager she'd hired . . . and he didn't understand the system.

I recently scanned photos, taken 20 years ago, of that pump room and I realized that I hadn't really planned for a system someone beside myself could operate. The customer wanted the absolute max quality water with zero chemical odor, and I delivered that. I swam laps in that pool, and it was the nicest indoor pool water I've ever been in.

But it was a complex system that hardly anyone could operate, unless I was training and supporting them. I'm sure it's been torn out, now.