Let's await Kelly Duffie's reply. He is the best expert on this forum.
But, I know this much...in soft acidic water, copper sulfate is toxic to many species of fish. Chelated forms are much better.
Plus, chelated forms have a different impact on pond soils. Kelly will know this answer.
Also, copper is toxic to trout.


Teach a man to grow fish...
He can teach to catch fish...