All of a sudden my pond is green

[brokensword]

The reason for the green water is the sun. More than once, I filled an empty pond with fresh clean water and watched free floating algae quickly start to invade. I've never had fish. UV has already cured my problem.

you'll get algae even if you don't have sun, though of course, it exacerbates the process. I've had algae grow in my tap water filter, sitting in a dark corner even with heavy use. We'll put you in the UVU club, then.

(@addy1 ; here's another; UVU = UV users)