- How old is your pond?

Started it up last September.

- Any other plants in there?

Water Lilly seems to be doing fine. Watercress, water hyacinth, parrot's
feather, creeping primrose, nada.

- Where do you get your water from?

City water.

- Does any sort of runoff get into your pond?

No (and it doesn't rain here this time of year anyway)

- Any herbicides sprayed on your property or nearby property lately?

Not that I know of. My gardener does fertilize my lawn from time to time,
but it's not adjacent to the pond.

- Your zone, your general area, your spring conditions?

Zone 10b, about 4 miles from the beach in Southern CA.

- Water test results?

I'll test again this weekend. At last test, everything was pretty good
(about 6 weeks ago)

- Color of the new algae, brown, blue-green?

It's light green.

- Does it smell?

Yeah, but not real strong

That's all I can think of. Someone will chime in I'm sure (this is not my
area
of expertise).