mark Bannister wrote:

She thought she was doing a good thing, and fortunately there are no
fish yet. The pond was supposed to be up and running last year, but
I
just now got the tile finished. It's a small formal pond, about 700
gallons, tiled with granite. My daughter used half a bottle of
dishwashing soap to clean it. Now it's a great big bubble bath.
I've rinsed and rinsed and still have a bubble bath. Will sunlight
eventually break down the soap?

Once it's dilute enough (it probably is already), it'll be bacteria,
not light, that will decompose it. And make it stink in the process.
And consume oxygen.

Robert in the Bronx