Thanks y'all. If only it were just an inch a day. This is like half the water in the pond. I'll turn the big pump off for a day & see if it's the culprit. Not the waterfall pump but the InPond 5-in-1 from Lowe's. It's supposed to have a UV light to kill algae & that seems to be basically working. My pond is in the sun so it's hard not to have algae but the water is clear, not at all murky. That pump was $200 but if I don't need it maybe I can sell it & get some of my son's money back. smile

Trying again with video.

Pond