Michael . . .
No, we've never turned off the UV. Guess we could -- but never have?
Grant . . .
Fact: Will never again be without a Clarity unit.
Even with the best pond and practices, it removes stuff that has to be seen to be believed.
Here's a short series of pix by way of illustration:

. June: One month in, heavy feeding

. Nov series: Before cleaning

. After cleaning

. 1 minute after startup

. 5 minutes after startup

. 30 minutes after startup

. 1 1/2 hours after startup

. Typical morning foam this time of year/feeding

. Highly reflective water surface seen during morning feed (air and skimmers turned off)