I had always thought putting any soap in a pond or aquarium was a super
bad idea. But then, my boss told me yesterday that his uncle has a
large koi pond and was cleaning it this past weekend. Every year, he
takes the fish out, scrubs the liner bare (removing all the good
stuff), and then washes the pond with Joy dishwashing soap!! He
rinses, refills with city water (no dechlorinator), waits a few days,
puts the fish back and claims he NEVER has a problem. Somehow, I just
don't believe it!!!!!!!

Robyn
fishpondinfo.com