Lots of rain? What's your runoff situation like? Could something nasty be
running into the pond?

BV.


Good question.

A couple of months ago, we did get the house power washed. They used
bleach, but they didn't use it on the side of the house near the pond.
It's possible the wind could have blown some in, but I added De-Chlor
as a preventative afterwards.

Also, about that time, an exterminator came and sprayed around the
house. He uses a pyrethrin-based product. Again, though, we watched
him closely to make sure that he stayed away from the pond. I guess
it's not impossible some could have gotten in.

I can't think of anything else. We have no nearby neighbors and our
wastewater is discharged downhill of the pond. We don't use chemicals
on the lawn.

We did have an awful lot of algae this year, so I guess it's possible
we're a little oxygen depleted. We run an air bubbler in the pond
24/7 and we have a waterfall, though, and I haven't seen any fish
gasping for air at the surface of the water. I guess I need to check
early in the AM.

Joan