The pond has been great all summer, but suddenly my water lettuce is
yellowing, even the "pups". All the usual levels continue to be fine. I
have added potash every two weeks and have not done anything different.
Clarity is good; no algae problems; fish health great (even had some fry
show up this week!).

SO!

1. What might be causing the water lettuce to yellow?
2. Would adding the product Aquatic Plant Stimulant help,
and is it safe for my 4 sarasas and 1 goldfish?

We are scheduled to be part of the local "Battle of the Ponds" tour this
weekend, so I need some quick assistance.
Thanks in advance!

NJ
zone 5b